MOD = 998244353

def main():
    import sys
    N, K = map(int, sys.stdin.readline().split())
    if N == 1:
        if K == 0:
            print(1)
        else:
            print(0)
        return

    n = N - 1

    # Precompute m^K mod MOD for m in 0..n
    pow_mK = [0] * (n + 1)
    pow_mK[0] = 1 if K == 0 else 0
    for m in range(1, n + 1):
        pow_mK[m] = pow(m, K, MOD)

    # Precompute factorial and inverse factorial modulo MOD
    fact = [1] * (n + 1)
    for i in range(1, n + 1):
        fact[i] = fact[i - 1] * i % MOD

    inv_fact = [1] * (n + 1)
    inv_fact[n] = pow(fact[n], MOD - 2, MOD)
    for i in range(n - 1, -1, -1):
        inv_fact[i] = inv_fact[i + 1] * (i + 1) % MOD

    total = 0
    for m in range(0, n + 1):
        # Compute C(n, m) = fact[n] * inv_fact[m] * inv_fact[n - m] mod MOD
        c = fact[n] * inv_fact[m] % MOD
        c = c * inv_fact[n - m] % MOD
        term = c * pow_mK[m] % MOD
        total = (total + term) % MOD

    print(total)

if __name__ == "__main__":
    main()