
A DNA sequence is presented as a sequence of characters, which may be 'A', 'G', 'C' or 'T'. To align two DNA sequences, some gaps may be inserted to sequences so that two sequences have the same length. And then it is counted up for every pair of matched characters by a score matrix. Gnaileux Iew uses a minimal-score matrix hence the total score of alignment should be minimized. Following is the score matrix Gnaileux Iew uses: <br />
</span><center><span style="font-size: medium"><img src="http://poj.org