I was solving the problem A.Domino Pilling (https://codeforces.com/problemset/problem/50/A) and i did get the correct answer by printing out (m*n)/2. but then i was trying to solve it by recursion but i got an incorrect answer on a test case it worked fine with most of the test cases but when i tried 3x6 i got an incorrect answer. I cannot figure out whats wrong with the recursion solution. Please help me figure out. Thank you

This is the link for the solution https://codeforces.com/contest/50/submission/124366489