use warnings;
use strict;

open EVENTS_FILE, '<', 't1Vevents.txt' or die "Cannot open 't1Vevents.txt' $!";

my ( @array, %values );
while ( <EVENTS_FILE> ) {
    chomp;

    if ( /([dD][12])/ ) {
        $values{ lc $1 } = ( split /:/ )[ 1 ];
        }

    if ( /[dD]4/ ) {
         push @array, @values{ 'd1', 'd2' };
         }
    }
close EVENTS_FILE;

print @array;