use strict;
use warnings;

open my $fh, '<', $FILE2 or die "Can't open file2: $!\n";
my %hash = map split, <$fh>;

open $fh, '<', $FILE1 or die "Can't open file1: $!\n";
while ( <$fh> ) {
  my ( $k, $v ) = split;
  my $ok = ( defined $hash{$k} and $hash{$k} == $v ) ? 'OK' : 'WRONG' ;
  print join( "\t", $k, $ok, $v ), "\n";
}