#! perl -sw
use strict;

my %files;
while(<DATA>) {
	chomp;
	my ($type, $ts) = m/(..)(.*)/;
	$files{$type} = [] if not exists $files{$type};
	push @{$files{$type}}, $ts;
}
foreach my $type (keys %files) {
	print $type,$_,$/ for sort @{$files{$type}};
}

__DATA__
vs010101.000
ud010101.000
ve020202.000
eq131302.000
eq010101.000
vs031102.000
us020101.000
ve051001.000