#!/usr/bin/perl

# http://perlmonks.org/?node_id=1138167

use strict;
use warnings;

my $string1 = "IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
+IIIIIIIIIIIIIMMMMMMMMOOOOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMIIIIMMMMMMMM
+MMMMMOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMIIIMMMMMMMMMMMOOOOOOOOOO
+OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMMMMMIIIIIMMMMM
+MMMMMMOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMIIIMMMMMMMMMOOOOOOO
+OOOOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMMMIIIMMMMMMMMMOOOOOOOOOOOOOOOOOOO
+MMMMMMMMMIIIIIIIIIIIIIIIIIIIIIIIIIIIMMMMMMMMOMMMMMMMMMMMMM";

my $string2 = "IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
+IIIIIIIIIIIIMMMMMMMMMMMMOOOOOOOOOOOOOOOOOMMMMMMMMMMMMMMMMIIIIIMMMMMMM
+MMMMMMOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMMMMMMMIIIMMMMMMMMMMMMMMOOOOOOO
+OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMMMMMMMIIIMMMMMMM
+MMMMMMMMOOOOOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMMMMMMIIIMMMMMMMMMMMMMMMO
+OOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMMMMMMIIIMMMMMMMMMMMMOOOOOOOOOOOOOOOM
+MMMMMMMMMIIIIIIMMMMMMMMMMMMOOOOOOOOOOOOOOOOOMMMMMMMMMMMMII";

my $same = ($string1 ^ $string2) =~ /^\0/ ? 'SAME' : 'DIFFERENT';

my ($count1, $count2) = map scalar(() = /M+/g), $string1, $string2;

my $overlap5 = 0;
$overlap5 += substr($string2, $-[0], length $1) =~ /M{5}/
  while $string1 =~ /(M+)/g;

print "first letter $same,  M counts $count1 $count2,  overlap5 $overl
+ap5\n";
[download]