in c++ input parameter has type long, but 10e10 numbers can't fit into long, maybe change to long long?

There are multiple errors with test cases in c++:

1. m=6540715897, n=48. Test is expecting -1, while the real answer is 11
2. m=1 n=11 and any others where m<n, where test is expecting 0. While mathematically correct, 11 choose 0 = 1, the answer should be 1, as you cant paint with 0 colors