def count_ways(m, n): dp = [[1 for _ in range(n)] for _ in range(m)] for j in range(1, n): dp[0][j] = dp[0][j - 1] + dp[0][j] for i in range(1, m): dp[i][0] = dp[i - 1][0] + dp[i][0] for i in range(1, m): for j in range(1, n): dp[i][j] = dp[i - 1][j] + dp[i][j - 1] return dp[-1][-1] def main(): m, n = map(int, input().split()) print(count_ways(m, n)) if __name__ == "__main__": main()