#include <bits/stdc++.h>

using namespace std;

const int N = 1e6 + 5, P = 998244353;

int ksm(int x, int y = P - 2) {
    int res = 1;
    while (y) {
        if (y & 1) res = 1ll * res * x % P;
        x = 1ll * x * x % P;
        y >>= 1;
    }
    return res;
}

int f[N], s[N], pw[N], pwI[N];

signed main() {
    int n, m, res = 0; scanf("%d%d", &n, &m);
    int iv = ksm(m);
    for (int i = pw[0] = pwI[0] = 1; i <= n; ++i) {
        pw[i] = 1ll * pw[i - 1] * m % P;
        pwI[i] = 1ll * pwI[i - 1] * iv % P;
    }
    for (int i = 1; i + i + 1 <= n; ++i) {
        f[i] = (pw[i] - 1ll * pw[i] * s[i >> 1] % P + P) % P;
        res = (res + 1ll * pw[n - i - i] * f[i]) % P;
        s[i] = (s[i - 1] + 1ll * f[i] * pwI[i] % P * pwI[i]) % P;
    }
    printf("%d\n", res);
    return 0;
}