use strict;
use warnings;

my( @dates ) = ( '4-10-31', '14-11-31' );

foreach my $date ( @dates ) {
    my $string = $date;
    $string =~ s/^(\d+)/
        my $year=2000;
        substr($year,4-length($1),length($1))=$1;
        $year/e;
    print $string, "\n";
}