Por que, após a atualização do Ubuntu 12.04, a instalação não está sendo instalada?

14

Instalei o Ubuntu 12.04 em um computador. Tudo está bem sem atualização. Logo após a instalação, ele estava mostrando cerca de 200 MB de atualizações para download. Desde então estou tentando instalar todas as atualizações. Agora está parcialmente concluído, alguns dos softwares (firefox, VLC) são atualizados. Ainda está mostrando atualizações de 39,3 MB para download e está falhando de novo e de novo. Toda vez que eu tentei instalar essas atualizações de 39.3 MB, isso mostra que ele não pode se conectar à Internet, mas não há problema com a minha conexão (indicador de rede mostra que está conectado e eu posso navegar e baixar qualquer coisa). Está me dando a seguinte mensagem:

Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/l/linux/linux-image-3.2.0-43-generic-pae_3.2.0-43.68_i386.deb Size mismatch
Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/l/linux/linux-headers-3.2.0-43-generic-pae_3.2.0-43.68_i386.deb Size mismatch

Eu pensei que isso é um problema com a lista de fontes. Então eu dei o seguinte comando

sudo rm -vf /var/lib/apt/lists/partial/*

Anteriormente, enfrentei um problema semelhante com um computador diferente. Naquela época, essa solução funcionou para mim, mas agora ainda estou enfrentando esse problema. Alguém por favor me ajude a resolver este problema.

Atualizar

Aqui está a saída de sudo apt-get update

Hit http://dl.google.com stable Release.gpg                                    
Hit http://archive.canonical.com precise Release.gpg                           
Get:1 http://extras.ubuntu.com precise Release.gpg [72 B]                      
Hit http://dl.google.com stable Release                                        
Hit http://us.archive.ubuntu.com precise Release.gpg                           
Hit http://archive.canonical.com precise Release                     
Hit http://dl.google.com stable/main i386 Packages                             
Hit http://extras.ubuntu.com precise Release                                   
Ign http://dl.google.com stable/main TranslationIndex                          
Get:2 http://us.archive.ubuntu.com precise-updates Release.gpg [198 B]
Hit http://archive.canonical.com precise/partner i386 Packages                 
Hit http://extras.ubuntu.com precise/main Sources                              
Hit http://us.archive.ubuntu.com precise-backports Release.gpg                 
Ign http://archive.canonical.com precise/partner TranslationIndex              
Hit http://extras.ubuntu.com precise/main i386 Packages                        
Hit http://us.archive.ubuntu.com precise-security Release.gpg                  
Ign http://extras.ubuntu.com precise/main TranslationIndex                     
Hit http://us.archive.ubuntu.com precise Release                               
Ign http://dl.google.com stable/main Translation-en_US                         
Get:3 http://us.archive.ubuntu.com precise-updates Release [49.6 kB]           
Ign http://dl.google.com stable/main Translation-en                            
Get:4 http://us.archive.ubuntu.com precise-updates Release [49.6 kB]           
Ign http://archive.canonical.com precise/partner Translation-en_US             
Ign http://archive.canonical.com precise/partner Translation-en                
Hit http://us.archive.ubuntu.com precise-backports Release                     
Hit http://us.archive.ubuntu.com precise-security Release                      
Ign http://extras.ubuntu.com precise/main Translation-en_US                    
Hit http://us.archive.ubuntu.com precise/main Sources                          
Ign http://extras.ubuntu.com precise/main Translation-en                       
Hit http://us.archive.ubuntu.com precise/restricted Sources                    
Hit http://us.archive.ubuntu.com precise/universe Sources                      
Hit http://us.archive.ubuntu.com precise/multiverse Sources                    
Hit http://us.archive.ubuntu.com precise/main i386 Packages                    
Hit http://us.archive.ubuntu.com precise/restricted i386 Packages              
Hit http://us.archive.ubuntu.com precise/universe i386 Packages                
Hit http://us.archive.ubuntu.com precise/multiverse i386 Packages              
Hit http://us.archive.ubuntu.com precise/main TranslationIndex                 
Hit http://us.archive.ubuntu.com precise/multiverse TranslationIndex           
Hit http://us.archive.ubuntu.com precise/restricted TranslationIndex
Hit http://us.archive.ubuntu.com precise/universe TranslationIndex
Get:5 http://us.archive.ubuntu.com precise-updates/main Sources [383 kB]
Get:6 http://us.archive.ubuntu.com precise-updates/main Sources [383 kB]       
Get:7 http://us.archive.ubuntu.com precise-updates/restricted Sources [5,467 B]
Get:8 http://us.archive.ubuntu.com precise-updates/universe Sources [87.1 kB]  
Get:9 http://us.archive.ubuntu.com precise-updates/universe Sources [87.1 kB]  
Get:10 http://us.archive.ubuntu.com precise-updates/universe Sources [87.1 kB] 
Get:11 http://us.archive.ubuntu.com precise-updates/multiverse Sources [6,582 B]
Get:12 http://us.archive.ubuntu.com precise-updates/main i386 Packages [625 kB]
Get:13 http://us.archive.ubuntu.com precise-updates/restricted i386 Packages [10.0 kB]
Get:14 http://us.archive.ubuntu.com precise-updates/universe i386 Packages [203 kB]
Get:15 http://us.archive.ubuntu.com precise-updates/multiverse i386 Packages [13.8 kB]
Get:16 http://us.archive.ubuntu.com precise-updates/multiverse i386 Packages [13.8 kB]
100% [16 Packages bzip2 0 B] [Connecting to us.archive.ubuntu.com (91.189.91.14
bzip2: Compressed file ends unexpectedly;
    perhaps it is corrupted?  *Possible* reason follows.
bzip2: Inappropriate ioctl for device
    Input file = (stdin), output file = (stdout)

It is possible that the compressed file(s) have become corrupted.
You can use the -tvv option to test integrity of such files.

You can use the 'bzip2recover' program to attempt to recover
data from undamaged sections of corrupted files.

Hit http://us.archive.ubuntu.com precise-updates/main TranslationIndex         
Hit http://us.archive.ubuntu.com precise-updates/multiverse TranslationIndex   
Hit http://us.archive.ubuntu.com precise-updates/restricted TranslationIndex   
Hit http://us.archive.ubuntu.com precise-updates/universe TranslationIndex     
Hit http://us.archive.ubuntu.com precise-backports/main Sources                
Hit http://us.archive.ubuntu.com precise-backports/restricted Sources          
Hit http://us.archive.ubuntu.com precise-backports/universe Sources
Hit http://us.archive.ubuntu.com precise-backports/multiverse Sources
Hit http://us.archive.ubuntu.com precise-backports/main i386 Packages
Hit http://us.archive.ubuntu.com precise-backports/restricted i386 Packages
Hit http://us.archive.ubuntu.com precise-backports/universe i386 Packages
Hit http://us.archive.ubuntu.com precise-backports/multiverse i386 Packages
Hit http://us.archive.ubuntu.com precise-backports/main TranslationIndex
Hit http://us.archive.ubuntu.com precise-backports/multiverse TranslationIndex
Hit http://us.archive.ubuntu.com precise-backports/restricted TranslationIndex
Hit http://us.archive.ubuntu.com precise-backports/universe TranslationIndex
Hit http://us.archive.ubuntu.com precise-security/main Sources
Hit http://us.archive.ubuntu.com precise-security/restricted Sources
Hit http://us.archive.ubuntu.com precise-security/universe Sources
Hit http://us.archive.ubuntu.com precise-security/multiverse Sources
Hit http://us.archive.ubuntu.com precise-security/main i386 Packages
Hit http://us.archive.ubuntu.com precise-security/restricted i386 Packages
Hit http://us.archive.ubuntu.com precise-security/universe i386 Packages
Hit http://us.archive.ubuntu.com precise-security/multiverse i386 Packages
Hit http://us.archive.ubuntu.com precise-security/main TranslationIndex
Hit http://us.archive.ubuntu.com precise-security/multiverse TranslationIndex
Hit http://us.archive.ubuntu.com precise-security/restricted TranslationIndex
Hit http://us.archive.ubuntu.com precise-security/universe TranslationIndex
Hit http://us.archive.ubuntu.com precise/main Translation-en
Hit http://us.archive.ubuntu.com precise/multiverse Translation-en
Hit http://us.archive.ubuntu.com precise/restricted Translation-en
Hit http://us.archive.ubuntu.com precise/universe Translation-en
Hit http://us.archive.ubuntu.com precise-updates/main Translation-en           
Hit http://us.archive.ubuntu.com precise-updates/multiverse Translation-en
Hit http://us.archive.ubuntu.com precise-updates/restricted Translation-en
Hit http://us.archive.ubuntu.com precise-updates/universe Translation-en
Hit http://us.archive.ubuntu.com precise-backports/main Translation-en
Hit http://us.archive.ubuntu.com precise-backports/multiverse Translation-en
Hit http://us.archive.ubuntu.com precise-backports/restricted Translation-en
Hit http://us.archive.ubuntu.com precise-backports/universe Translation-en
Hit http://us.archive.ubuntu.com precise-security/main Translation-en
Hit http://us.archive.ubuntu.com precise-security/multiverse Translation-en
Hit http://us.archive.ubuntu.com precise-security/restricted Translation-en
Hit http://us.archive.ubuntu.com precise-security/universe Translation-en
Fetched 935 kB in 3min 39s (4,261 B/s)
W: Failed to fetch gzip:/var/lib/apt/lists/partial/us.archive.ubuntu.com_ubuntu_dists_precise-updates_multiverse_binary-i386_Packages  Hash Sum mismatch

E: Some index files failed to download. They have been ignored, or old ones used instead.
    
por tuxtu 20.05.2013 / 13:42

2 respostas

15

Meu problema está resolvido agora. Estou postando aqui a solução passo a passo. Da saída de sudo apt-get update , estava enfrentando o seguinte problema:

W: Failed to fetch gzip:/var/lib/apt/lists/partial/us.archive.ubuntu.com_ubuntu_dists_precise-updates_multiverse_binary-i386_Packages  Hash Sum mismatch

E: Some index files failed to download. They have been ignored, or old ones used instead.

Para resolver este problema, eu digitei os seguintes comandos, um por um.

sudo rm /var/lib/apt/lists/* -vf
sudo apt-get clean
sudo apt-get autoremove
sudo apt-get update
sudo apt-get dist-upgrade 

Em seguida, a saída foi

audity@auditypc:~$ sudo rm /var/lib/apt/lists/* -vf
[sudo] password for audity: 
removed '/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_partner_binary-i386_Packages'
removed '/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_Release'
removed '/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_Release.gpg'
removed '/var/lib/apt/lists/dl.google.com_linux_talkplugin_deb_dists_stable_main_binary-i386_Packages'
removed '/var/lib/apt/lists/dl.google.com_linux_talkplugin_deb_dists_stable_Release'
removed '/var/lib/apt/lists/dl.google.com_linux_talkplugin_deb_dists_stable_Release.gpg'
removed '/var/lib/apt/lists/extras.ubuntu.com_ubuntu_dists_precise_main_binary-i386_Packages'
removed '/var/lib/apt/lists/extras.ubuntu.com_ubuntu_dists_precise_main_source_Sources'
removed '/var/lib/apt/lists/extras.ubuntu.com_ubuntu_dists_precise_Release'
removed '/var/lib/apt/lists/extras.ubuntu.com_ubuntu_dists_precise_Release.gpg'
removed '/var/lib/apt/lists/lock'
rm: cannot remove '/var/lib/apt/lists/partial': Is a directory
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_main_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_main_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_main_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_main_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_multiverse_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_multiverse_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_multiverse_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_multiverse_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_Release'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_Release.gpg'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_restricted_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_restricted_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_restricted_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_restricted_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_universe_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_universe_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_universe_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-backports_universe_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_main_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_main_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_main_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_main_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_multiverse_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_multiverse_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_multiverse_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_multiverse_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_Release'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_Release.gpg'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_restricted_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_restricted_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_restricted_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_restricted_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_main_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_main_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_main_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_main_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_multiverse_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_multiverse_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_multiverse_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_multiverse_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_Release'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_Release.gpg'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_restricted_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_restricted_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_restricted_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_restricted_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_universe_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_universe_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_universe_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-security_universe_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_universe_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_universe_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_universe_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise_universe_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_main_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_main_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_main_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_main_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_multiverse_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_multiverse_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_multiverse_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_multiverse_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_Release'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_Release.gpg'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_restricted_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_restricted_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_restricted_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_restricted_source_Sources'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_universe_binary-i386_Packages'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_universe_i18n_Index'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_universe_i18n_Translation-en'
removed '/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise-updates_universe_source_Sources'
audity@auditypc:~$ sudo apt-get clean
[sudo] password for audity: 
audity@auditypc:~$ sudo apt-get autoremove
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
audity@auditypc:~$ sudo apt-get update
Get:1 http://dl.google.com stable Release.gpg [198 B]                          
Get:2 http://us.archive.ubuntu.com precise Release.gpg [198 B]                 
Get:3 http://dl.google.com stable Release [1,347 B]                            
Get:4 http://extras.ubuntu.com precise Release.gpg [72 B]                      
Get:5 http://archive.canonical.com precise Release.gpg [198 B]                 
Get:6 http://dl.google.com stable/main i386 Packages [763 B]                   
Get:7 http://us.archive.ubuntu.com precise-updates Release.gpg [198 B]         
Get:8 http://extras.ubuntu.com precise Release [11.9 kB]                       
Ign http://dl.google.com stable/main TranslationIndex                          
Get:9 http://archive.canonical.com precise Release [7,078 B]                   
Get:10 http://extras.ubuntu.com precise/main Sources [8,130 B]                 
Get:11 http://us.archive.ubuntu.com precise-backports Release.gpg [198 B]      
Get:12 http://archive.canonical.com precise/partner i386 Packages [8,261 B]    
Get:13 http://extras.ubuntu.com precise/main i386 Packages [10.8 kB]           
Ign http://archive.canonical.com precise/partner TranslationIndex              
Get:14 http://us.archive.ubuntu.com precise-security Release.gpg [198 B]       
Ign http://extras.ubuntu.com precise/main TranslationIndex                     
Get:15 http://us.archive.ubuntu.com precise Release [49.6 kB]                  
Ign http://dl.google.com stable/main Translation-en_US                         
Get:16 http://us.archive.ubuntu.com precise Release [49.6 kB]                  
Ign http://dl.google.com stable/main Translation-en                            
Get:17 http://us.archive.ubuntu.com precise-updates Release [49.6 kB]          
Ign http://extras.ubuntu.com precise/main Translation-en_US                    
Ign http://archive.canonical.com precise/partner Translation-en_US             
Get:18 http://us.archive.ubuntu.com precise-updates Release [49.6 kB]          
Ign http://extras.ubuntu.com precise/main Translation-en                       
Ign http://archive.canonical.com precise/partner Translation-en                
Get:19 http://us.archive.ubuntu.com precise-backports Release [49.6 kB]        
Get:20 http://us.archive.ubuntu.com precise-backports Release [49.6 kB]        
Get:21 http://us.archive.ubuntu.com precise-backports Release [49.6 kB]        
Ign http://us.archive.ubuntu.com precise-backports Release                     
E: GPG error: http://us.archive.ubuntu.com precise-backports Release: The following signatures were invalid: NODATA 2
audity@auditypc:~$

Agora, estava enfrentando um erro de GPG. Para resolver isso eu tentei o seguinte

$ sudo -i
# apt-get clean
# cd /var/lib/apt
# mv lists lists.old
# mkdir -p lists/partial
# apt-get clean
# apt-get update
# exit

Após este comando. Eu entrei nos comandos finais.

sudo apt-get dist-upgrade
    
por tuxtu 28.05.2013 / 05:29
8

Apenas a incompatibilidade de soma de hash da lista de pacotes de arquivos dos EUA em algumas instalações 12.04.5 novas. Solução mais curta que funcionou para mim pelo menos:

# rm /var/lib/apt/lists/partial/us.archive.ubuntu.com_ubuntu_dists_precise_*
# rm /var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_precise*
# aptitude update
... now worked ...
    
por dantie 20.05.2015 / 17:53