A walk on a grid

Given a n*n grid with every cell in it consisting of number 1,2 or 3. A person standing at cell (a,b) can go to (c,d) only if (c-a)+(d-b)=1 and c>=a and d>=b. The cost of a walk is the product of all the numbers on the cells visited in that walk. Now you have to answer q queries of the form: for each given x, y -> You start at (1,1) and end your walk in the cell (n,n), now you want to know if th