open my $fh, '<', $file1 or die $!;
my %replace = map { chomp; split /-/, $_, 2 } <$fh>;
my $re = join '|', sort { length $b <=> length $a } keys %replace;
close $fh;
open my $in, '<', $file2 or die $!;
open my $out, '>', $file3 or die $!;
while (my $line = <$in>) {
  $line =~ s/\b($re)\b/$replace{$1}/g;
  print $out $line;
}