Write a Perl subroutine that computes a maximal local aligned segment.
The input to the subroutine is

1. $q (query sequence)
2. $t (target sequence)
3. $kmer (a substring of length 3 that is contained in $q and $t)
4. $threshold (defined such that the maximal segment score will reduce by 
	       at most threshold if further extended)

For example, suppose the input $q and $t are

$t: ACCTGTAGG
$q: ATGTC

$kmer="TGT", and $threshold=-2. Also suppose the match score=10 and mismatch=-2. 

Then the kmer-hit has score 30. But if extended it becomes

CTGTA
ATGTC

which has a reduction of -4. This is less than the threshold -2 and so the maximal aligned
segment is 

TGT
TGT

Submit your solution as a file called <firstname>HW11.pl to the teaching assistant Shikha Kaushal
(shikha.kaushal@gmail.com). Replace <firstname> with your first name.