#include <algorithm>
#include <iostream>
#include <vector>

#include <atcoder/modint>
#include <atcoder/convolution>

using mint = atcoder::modint998244353;
using fps = std::vector<mint>;

fps fps_inv(const fps& f) {
    int n = f.size();
    fps f_fft, g_fft;
    fps g{ f[0].inv() };
    for (int k = 1; k < n; k *= 2) {
        f_fft = fps(f.begin(), f.begin() + std::min(2 * k, n));
        g_fft = g;
        f_fft.resize(2 * k), g_fft.resize(2 * k);
        atcoder::internal::butterfly(f_fft);
        atcoder::internal::butterfly(g_fft);

        fps fg(2 * k);
        for (int i = 0; i < 2 * k; ++i) fg[i] = f_fft[i] * g_fft[i];
        atcoder::internal::butterfly_inv(fg);
        fg.erase(fg.begin(), fg.begin() + k), fg.resize(2 * k);
        atcoder::internal::butterfly(fg);
        for (int i = 0; i < 2 * k; ++i) fg[i] *= g_fft[i];
        atcoder::internal::butterfly_inv(fg);
        const mint iz = mint(2 * k).inv(), c = -iz * iz;
        g.resize(2 * k);
        for (int i = 0; i < k; ++i) g[k + i] = fg[i] * c;
    }
    g.resize(n);
    return g;
}

int main() {
    int n;
    long long m;
    std::cin >> n >> m;
    fps f(n + 1);
    f[1] = 1;
    for (int i = 2; i <= n; ++i) f[i] += f[i - 1] - f[i - 2];
    for (int i = 1; i <= n; ++i) f[i] *= std::max(0LL, m - i + 1);
    f[0] = 1;
    for (int i = 1; i <= n; ++i) f[i] = -f[i];
    std::cout << fps_inv(f)[n].val() << std::endl;
}