$s = "evian-eauminerale";
$t = "borisvian-ecrivain";

foreach my $i (1..length($s)) {
         foreach my $j (1..length($t)) {
                if (substr($s, $i-1, 1) eq substr($t, $j-1, 1)) {
                   $M[$i][$j] = $M[$i-1][$j-1]+1;
                   $M[$i-1][$j-1] = 0;
                }
        }
}

foreach @array (@M) {
        foreach $element (@array) {
                print "$element ";
        }
        print "\n";
}