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

using i64 = long long;

template <int P>
struct Modint {
    int v;

    constexpr Modint() : v(0) {}
    constexpr Modint(i64 v_) : v(v_ % P) {
        if (v < 0) {
            v += P;
        }
    }
    constexpr explicit operator int() const { return v; }
    constexpr friend ostream& operator<<(ostream &out, Modint n) {
        return out << int(n);
    }
    constexpr friend istream& operator>>(istream &in, Modint &n) {
        i64 v;
        in >> v;
        n = Modint(v);
        return in;
    }

    constexpr friend bool operator==(Modint a, Modint b) {
        return a.v == b.v;
    }
    constexpr friend bool operator!=(Modint a, Modint b) {
        return a.v != b.v;
    }

    constexpr Modint operator-() {
        Modint res;
        res.v = v ? P - v : 0;
        return res;
    }

    constexpr Modint& operator++() {
        v++;
        if (v == P) v = 0;
        return *this;
    }
    constexpr Modint& operator--() {
        if (v == 0) v = P;
        v--;
        return *this;
    }
    constexpr Modint& operator+=(Modint o) {
        v -= P - o.v;
        v = (v < 0) ? v + P : v;
        return *this;
    }
    constexpr Modint& operator-=(Modint o) {
        v -= o.v;
        v = (v < 0) ? v + P : v;
        return *this;
    }
    constexpr Modint& operator*=(Modint o) {
        v = 1LL * v * o.v % P;
        return *this;
    }
    constexpr Modint& operator/=(Modint o) { return *this *= o.inv(); }

    constexpr friend Modint operator++(Modint &a, int) {
        Modint r = a;
        ++a;
        return r;
    }
    constexpr friend Modint operator--(Modint &a, int) {
        Modint r = a;
        --a;
        return r;
    }

    constexpr friend Modint operator+(Modint a, Modint b) {
        return Modint(a) += b;
    }
    constexpr friend Modint operator-(Modint a, Modint b) {
        return Modint(a) -= b;
    }
    constexpr friend Modint operator*(Modint a, Modint b) {
        return Modint(a) *= b;
    }
    constexpr friend Modint operator/(Modint a, Modint b) {
        return Modint(a) /= b;
    }

    constexpr Modint qpow(i64 p) {
        Modint res = 1, x = v;
        while (p > 0) {
            if (p & 1) { res *= x; }
            x *= x;
            p >>= 1;
        }
        return res;
    }
    constexpr Modint inv() {
        return qpow(P - 2);
    }
};

constexpr int P = 998244353;
using Mint = Modint<P>;

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);

    auto solve = [&]() {
        int n, m;
        cin >> n >> m;

        vector<Mint> pw(n + 1), ipw(n + 1);
        Mint im = Mint(m).inv();
        pw[0] = ipw[0] = 1;
        for (int i = 1; i <= n; i++) {
            pw[i] = pw[i - 1] * m;
            ipw[i] = ipw[i - 1] * im;
        }

        vector<Mint> dp(n + 1), pref(n / 2 + 1);

        for (int i = 1; i <= n; i++) {
            dp[i] = pw[i] - pref[i / 2] * pw[i];
            if (i <= n / 2) {
                pref[i] = pref[i - 1] + dp[i] * ipw[2 * i];
            }
        }

        Mint ans = pw[n] - dp[n];
        if (n % 2 == 0) {
            ans -= dp[n / 2];
        }

        cout << ans << '\n';
    };
    
    solve();
    
    return 0;
}