Hi, I was trying to solve this problem from a coding test and came up with an O(n^4) solution which goes like first I will precompute the 2-D prefix sums of the entire grid and then for each cell naively Bruteforce for all possible solutions in n^2 operations, It would be great if you can share your insights/solutions for the problem. The contest is over 5 days back you can answer as late as you want until you are assured of this.