#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const int N = 1e6 + 5;
const ll mod = 998244353;

ll n, m, ans, f[N], g[N], sum[N];

inline ll qpow(ll a, ll b) {
	ll res = 1;
	while (b) {
		if (b & 1) {
			res = res * a % mod;
		}
		a = a * a % mod;
		b >>= 1;
	}
	return res;
}

inline ll inv(ll a) {
	return qpow(a, mod - 2);
}

inline void addmod(ll &x) {
	(x >= mod) && (x -= mod);
}

int main() {
	#ifdef LOCAL
		assert(freopen("test.in", "r", stdin));
		assert(freopen("test.out", "w", stdout));
	#endif
	ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
	cin >> n >> m;
	f[0] = 1, f[1] = m;
	g[0] = 1, sum[1] = g[1] = inv(m);
	for (int i = 2; i <= n; ++i) {
		f[i] = (mod + 1 - sum[i >> 1]) * qpow(m, i) % mod;
		g[i] = f[i] * inv(qpow(m, i << 1)) % mod;
		addmod(sum[i] = sum[i - 1] + g[i]);
	}
	addmod(ans = qpow(m, n) + mod - f[n]);
	if (!(n & 1)) {
		addmod(ans += mod - f[n >> 1]);
	}
	cout << ans << "\n";
	return 0;
}