#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
#define range(x) (x).begin(), (x).end()
const int dir[][2] = {1, 0, -1, 0, 0, 1, 0, -1};

const ll mod = 998244353;
ll qpow(ll a, ll b)
{
    ll ans = 1;
    a %= mod;
    for (; b; b >>= 1) {
        if (b & 1)
            ans = ans * a % mod;
        a = a * a % mod;
    }
    return ans % mod;
}
void solve()
{
    int n, m;
    cin >> n >> m;

    ll ans = qpow(m, n);
    for (int i = 1; i <= m; ++i) {
        (ans += 2 * (qpow(m, n) - qpow(i, n) + mod)) %= mod;
    }
    cout << ans << '\n';
    // ans *= 2;
    // ans %= mod;
    // ans -= m;
    // ans += mod;
    // ans %= mod;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--)
        solve();
    return 0;
}