#!/usr/bin/perl
use warnings;
use strict;

use Data::Dumper;

open my $ENGLISH, '<', 'corpus.e' or die $!;
open my $FOREIGN, '<', 'corpus.f' or die $!;
chomp(my @sents_en = <$ENGLISH>);
chomp(my @sents_f  = <$FOREIGN>);

my %uniform;

for my $sentence_index (0 .. $#sents_en) {
    my @words_en = split ' ', $sents_en[$sentence_index];
    my @words_f =  split ' ', $sents_f[$sentence_index];

    for my $word_index (0 .. $#words_en) {
        $uniform{ $words_en[$word_index] }{$_}++ for @words_f;
    }
}

for my $word (keys %uniform) {
    $uniform{$word} = keys %{ $uniform{$word} };
}

print Dumper \%uniform;