MOD = 998244353

def main():
    import sys
    N, M = map(int, sys.stdin.readline().split())
    max_m = min(M + 1, N + 1)
    max_m = min(max_m, N + 1)  # Ensure it's up to N+1
    
    # Precompute factorial and inverse factorial mod MOD up to 2001
    max_fact = max_m
    fact = [1] * (max_fact + 1)
    for i in range(1, max_fact + 1):
        fact[i] = fact[i-1] * i % MOD
    
    inv_fact = [1] * (max_fact + 1)
    inv_fact[max_fact] = pow(fact[max_fact], MOD-2, MOD)
    for i in range(max_fact - 1, -1, -1):
        inv_fact[i] = inv_fact[i+1] * (i+1) % MOD
    
    def comb(m, k):
        if k < 0 or k > m:
            return 0
        return fact[m] * inv_fact[k] % MOD * inv_fact[m - k] % MOD
    
    ans = 0
    for m in range(1, max_m + 1):
        if m > M + 1:
            continue
        res = 0
        for k in range(0, m + 1):
            sign = -1 if (m - k) % 2 else 1
            c = comb(m, k)
            a = 2 * M + 1 + k - m
            a_mod = a % MOD
            a_pow = pow(a_mod, N, MOD)
            term = sign * c * a_pow
            term %= MOD
            res = (res + term) % MOD
        res = res * m % MOD
        ans = (ans + res) % MOD
    print(ans % MOD)

if __name__ == "__main__":
    main()