mod = 998244353


def main():
    import sys
    from itertools import combinations_with_replacement
    input = sys.stdin.readline

    def guchoku(N, M):
        res = 0
        for p in combinations_with_replacement(list(range(M+1)), 2 * N):
            p = list(p)
            #print(p)
            for i in range(N):
                res += p[i*2+1] - p[i*2]
        return res

    N, M = map(int, input().split())

    #print(guchoku(N, M))

    upper = N
    lower = 1
    for i in range(2 * N + 1):
        upper = (upper * (M + 2 * N - i)) % mod
        lower = (lower * (2 * N + 1 - i)) % mod
    print((upper * pow(lower, mod - 2, mod)) % mod)


if __name__ == '__main__':
    main()