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

using Mint = atcoder::modint998244353;

int main()
{
    int N, M;
    cin >> N >> M;
    if (M == 1)
    {
        cout << 1 << endl;
        return 0;
    }
    vector<Mint> C(N + 1, 0);

    for (int i = 2; i <= M; ++i)
    {
        for (int base = 1; base <= N; base += i)
        {
            if (base <= N)
                C[base]++;
            if (base + i - 1 <= N)
                C[base + i - 1]--;
        }
    }
    C.erase(C.begin());
    vector<Mint> D(N + 1, 0);
    D[0] = 1;

    function<void(int, int)> DnC = [&](int L, int R)
    {
        if (L == R)
            return;
        int M = (L + R) / 2;
        DnC(L, M);

        vector<Mint> V(D.begin() + L, D.begin() + M + 1);
        vector<Mint> Co(C.begin(), C.begin() + (R - L));
        vector<Mint> ans = atcoder::convolution(V, Co);
        for (int i = M + 1; i <= R; ++i)
            D[i] += ans[i - (M + 1) + (int)V.size() - 1];

        DnC(M + 1, R);
    };

    DnC(0, N);
    cout << (Mint(M).pow(N) - D.back()).val() << endl;
}