C:\>perl
my %hash1 = (1 ,2,3,4,5,6);
my %hash2 = (2,3,4,5,6,7);

while( my ($c,$d) = each %hash1 ){
    print $c," .. ", $d,"\n";
    while( my ($e,$f) = each %hash2 ){
        print "    $e .. $f\n";
    }
}
^D
1 .. 2
    6 .. 7
    4 .. 5
    2 .. 3
3 .. 4
    6 .. 7
    4 .. 5
    2 .. 3
5 .. 6
    6 .. 7
    4 .. 5
    2 .. 3