def solve(self, cipher):
        """
        Abstract: N types, K holes, repeatable
        nCk when items are duplicated

        reference:
        dp algorithm: https://github.com/derekhh/HackerRank/blob/master/k-candy-store.cpp

        :param cipher: the cipher
        """
        N, K = cipher
        return self.C[N + 1 - K][K] % MOD
dataset/ETHPy150Open algorhythms/HackerRankAlgorithms/K Candy Store.py/Solution.solve/swapped operands of `-`