use strict;

my %hash;
while(<>){
  (my $first, my $second) = split("|",$_);
  $hash{$first} = $second;
}

my $second
while(<>) {
  my $line = $_
  (my $first, $second) = split("|", $line);
}

foreach my $key (keys %hash){
  my @list = ($hash{$key}, $second);
  $joined = "@list";
  $hash{$key} = $joined;
}