Question $41.$ Longest Common Subsequence in a Grid You are given a n x m grid of characters, and two strings s$1$ and s$2.$ Your task is to find the length of the longest common subsequence of s$1$ and s$2$ that can be formed by moving horizontally or vertically in the grid, starting from any cell.Input: The first line contains integers n and m$.$ The next n lines each contain m characters, representing the grid. The last two lines contain strings s$1$ and s$2.$Output: Print the length of the longest common subsequence that can be formed.

If the annual interest rate of $5\mathrm{.}8\%,$ what is the present value of a stream of $4$ identical yearly pay