n, k = map(int, input().split())
mod = 998244353

def calc(x):
    num = pow(k, n, mod)
    num -= pow(x - 1, n, mod)
    num %= mod
    num -= ((k - x + 1) * n % mod) * pow(x - 1, n - 1, mod) % mod
    num %= mod
    return num

ans = 0
for i in range(1, k + 1):
    num = calc(i) - calc(i + 1)
    ans += i * num % mod
    ans %= mod
print(ans)