my $x = "EKFCNSVVDLYSNLSKPFLDIVLYIFKLTSAIGAQGPA----SMMAYLVV";
my $y = "ERFCRQLSSMASKLI-------ISPFTLVYYTYQCFQSTGWPVSIFGYFI";
my $z = $x^$y;
my $score = ($z =~ tr/\0//);
return $score/length($x)