#include <bits/stdc++.h>
using namespace std;
const int MOD = 998244353;

int n, m, dp[1000005];
int main() {
    scanf("%d%d", &n, &m);
    dp[0] = 1;
    for(int i = 1; i <= n; i++) {
        dp[i] = 1LL * dp[i - 1] * m % MOD;
        if(i < n && i % 2 == 0) dp[i] = (dp[i] - dp[i / 2] + MOD) % MOD;
    }
    
    int ans = 1;
    for(int i = 1; i <= n; i++) ans = 1LL * ans * m % MOD;
    ans = (ans - dp[n] + MOD) % MOD;
    printf("%d\n", ans);
    return 0;
}