#ifdef LOCAL
#include "stdafx.h"
#else
#include <bits/stdc++.h>
#define IL inline
#define LL long long
#define eb emplace_back
#define sz(v) ((int) (v).size())
#define L(i, j, k) for (int i = (j); i <= (k); ++i)
#define R(i, j, k) for (int i = (j); i >= (k); --i)
#define FIO(FILE) freopen(FILE".in", "r", stdin), freopen(FILE".out", "w", stdout)
using namespace std;

using vi = vector<int>;
#endif

constexpr int N = 1e6 + 9;
constexpr int P = 998244353;
int n, m, f[N], g[N], s[N];

IL constexpr int qpow (int b, int k = P - 2) {
  int r = 1;
  for (; k; k >>= 1, b = (LL)b * b % P) if (k & 1) r = (LL)r * b % P;
  return r;
}

int main () {
  ios::sync_with_stdio(0), cin.tie(0);
  cin >> n >> m;
  g[1] = m;
  s[1] = qpow(m);
  L (i, 2, n - 1) {
    f[i] = (LL)s[i / 2] * qpow(m, i) % P;
    g[i] = (qpow(m, i) + P - f[i]) % P;
    s[i] = (s[i - 1] + (LL)g[i] * qpow(m, P - 1 - 2 * i)) % P;
  }
  cout << (LL)s[(n - 1) / 2] * qpow(m, n) % P << '\n';
}
// I love WHQ!