MOD = 998244353

n, k = map(int, input().split())
dp = [0] * k
for i in range(k):
    dp[i] = pow(k - i, n, MOD) + pow(k - i, n - 1, MOD) * i * n % MOD
    dp[i] %= MOD
    
for i in range(k - 1):
    dp[i] -= dp[i + 1]

ans = 0
for i in range(k):
    ans += dp[i] * (k - i)
    ans %= MOD
    
print(ans)