#include<bits/stdc++.h>
using namespace std;
#define V vector
#define pb push_back

typedef long long LL;

const int mod = 998244353;
LL qpow(int x, LL k) {
    LL ans = 1;
    while(k) {
        if(k & 1) ans = ans * x % mod;
        k >>= 1;
        x = 1LL * x * x % mod;
    }
    return ans;
}


void solve() {
    int n; cin >> n;
    int m; cin >> m;
    LL ans = 0;
    for(int x = 1; x <= m; x++) {
        ans += 2LL * qpow(m, n) - 2 * qpow(x, n);
    }
    ans %= mod;
    if(ans < 0) ans += mod;
    
    ans += qpow(m, n);
    if(ans >= mod) ans -= mod;
    if(ans < 0)  ans += mod;
    cout << ans << endl;
    
}
int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    // int t; cin >> t;
    // while(t--) solve();
    solve();
}