#include <bits/stdc++.h>

using namespace std;

using pii = pair<int, int>;
using ll = long long;
const int N = 2000010, MOD = 998244353, INF = 0x3f3f3f3f;
int n, m, w[N];

ll k;
inline ll qmi(ll a, ll b, ll c) { ll res = 1; while (b) { if (b & 1) res = res * a % c; a = a * a % c; b >>= 1; } return res; }
struct mtx {
    vector<vector<ll> > a;
    int n, m;
    mtx(int _n, int _m) {
        n = _n, m = _m;
        a = vector<vector<ll> >(n + 1, vector<ll>(m + 1));
    }

    mtx operator*(const mtx& w) const {
        mtx res(n, m);
        res.n = n, res.m = w.m;
        for (int k = 1; k < m + 1; k++)
            for (int i = 1; i < n + 1; i++)
                for (int j = 1; j < w.m + 1; j++)
                    res.a[i][j] = (res.a[i][j] + a[i][k] * w.a[k][j]) % MOD;
        return res;
    }
};
mtx cal(mtx st, mtx x, ll k) {
    mtx res = st;
    while (k) {
        if (k & 1) {
			res = x * res;
        }
        k >>= 1;
        x = x * x;
    }
    return res;
}

void solve() {
    scanf("%d%lld", &n, &k);
    n <<= 2;
    n++;
    mtx x(n, 1);
    x.a[1][1] = 1;
    mtx f(n, n);
    for (int i = 1; i < n; i++) {
        if (i % 4 == 1) f.a[1][i] = 4 * qmi(5, MOD - 2, MOD) % MOD;
        else f.a[1][i] = 3 * qmi(5, MOD - 2, MOD) % MOD;
    }
    for (int i = 1; i < n; i++)
        if (i % 4 != 1)
            f.a[2][i] = qmi(5, MOD - 2, MOD);
    for (int i = 2; i <= n; i++) f.a[i][i - 1] = qmi(5, MOD - 2, MOD) % MOD;
    auto u = cal(x, f, k);
    printf("%lld\n", u.a[n][1]);
}

int main() {
    int T = 1;
    // scanf("%d", &T);
    while (T--) solve();
    return 0;
}