#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 4e5 + 10;
const int mod = 998244353;
int n, k;
int f[N];
int qmi(int a, int k) {
    int res = 1;
    a = a % mod;
    while (k) {
        if (k & 1) res = res * a % mod;
        k >>= 1;
        a = a * a % mod;
    }
    return res;
}

signed main() {
    cin >> n >> k;
    int res = 0;
    for (int i = k; i >= 1; i--) {
        f[i] = qmi(k, n);
        int a = (k - i + 1) * n % mod * qmi(i - 1, n - 1) % mod;
        int b = qmi(i - 1, n) % mod;
        f[i] = (f[i] - a + mod - b + mod) % mod;
        res = res + ((f[i] - f[i + 1] + mod) * i) % mod;

        res %= mod;
    }
    cout << res << endl;
}