open(IN,'/etc/passwd');
@unames = ();
for $i (<IN>)
{
	($x) =  split(':',$i,2);
	push(@unames,$x);

}

for $i (0..$#unames)
{

	@chars = split(//,@unames[$i]);

	for $j ($i+1..$#unames)
	{
		for $k (a..z)
		{
			$flag{$k} = 0;
		}
		for $k (@chars)
		{

			if (@unames[$j] =~ /$k/)
			{
				$flag{$k} = $flag{$k} + 1;
			}
		}
		$s = 0;
		for $x (a..z)
		{
			if ($flag{$x} > 0)
			{
				$s++;
				#print "@unames[$i] - @unames[$j], $x - $flag{$x} \n"
			}
		}
		if ($s >= 5)
		{
			print "\t@unames[$i] - @unames[$j]\n"	;
		}
	}
}