points$)$ As described in class, the longest common subsequence $($ICS$)$ algorithm with two strings of lengths m and n uses a matrix of m x n$,$ thus it has a memory cost of $9($mn$).$ If the strings are long $($e$.$g$.1000$s of symbols$),$ this is a big matrix. Assume that we do not need to find out the actual ICS, but only its length. Describe a