Write a Perl program that prints the pairwise sequence alignment score of data in
the file "dna.fasta". Use match=+2, mismatch=-1, and gap=-2. 

For example, if dna.fasta is

>human
ACCGTTAAG
>mouse
--CGTTCA-

then the program should print 3.

Submit your solution as a file called <firstname>HW6.pl to the teaching assistant Shikha Kaushal
(shikha.kaushal@gmail.com). Replace <firstname> with your first name.