#include<bits/stdc++.h>
#define int long long
using namespace std;
int read(){
	int s = 0, f = 1;char ch = getchar();
	while(!isdigit(ch)){if(ch == '-')f = -1;ch = getchar();}
	while(isdigit(ch)){s = s * 10 + ch - '0';ch = getchar();}
	return s * f;
}
void write(int x){
    if(x < 0){putchar('-'); x = -x;}
    if(x > 9) write(x / 10);
    putchar(x % 10 + '0');
}
const int MAXN = 1e6 + 5, MOD = 998244353;
int fpow(int a, int b){
	int res = 1;
	while(b){
		if(b & 1ll)res = res * a % MOD;
		a = a * a % MOD;
		b >>= 1ll;
	}
	return res;
}
int n, m, ans, f[MAXN], pw[MAXN];
signed main(){
	n = read(), m = read();
	pw[0] = 1;
	for(int i = 1;i <= n;i ++)pw[i] = pw[i - 1] * m % MOD;
	f[1] = m;
	for(int i = 2;i <= n;i ++){
		f[i] = f[i - 1] * m % MOD;
		if(i % 2 == 0)f[i] = (f[i] - f[i >> 1] + MOD) % MOD;
	} 
	for(int i = 1;i * 2 < n;i ++)ans += f[i] * pw[n - 2 * i] % MOD, ans %= MOD;
	printf("%lld\n", ans);
	return 0;
}