Get unique keys from different hashes

- As we konw, keys in a hash are unique, but not the values.

#!F:\Perl\bin\perl -w
use Data::Dumper;
use strict;

#Get unique keys from different hashes
my %hash1 = (a=>10,b=>20,c=>30);
my %hash2 = (a1=>10,b1=>20,c1=>30);
my %hash3 = (a=>10,b=>20,c=>30);
my %uniq_hash;
for my $each (keys(%hash1), keys(%hash2), keys(%hash3)) {
$uniq_hash{$each}++;
}
print "\n", $_ for (keys %uniq_hash),"\n";