#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <cstdio>
int main() {
    long long N;
    int K;
    std::scanf("%lld%d", &N, &K);
    constexpr int limit = 40000000;
    if(N > limit) return 12;
    static unsigned F[limit], R[limit];
    F[0] = F[1] = 1;
    for(int i = 2; i < N; ++i) {
        F[i] = F[i - 1] + F[i - 2];
    }
    for(int i = 0; i != N; ++i) R[i] = 1;
    while(K != 0) {
        if(K & 1) {
            for(int i = 0; i != N; ++i) {
                R[i] = (unsigned long long) R[i] * F[i] % 998244353;
            }
        }
        for(int i = 0; i != N; ++i) {
            F[i] = (unsigned long long) F[i] * F[i] % 998244353;
        }
        K >>= 1;
    }
    unsigned res = 0;
    for(int i = 0; i != N; ++i) res = (res + R[i]) % 998244353;
    printf("%u\n", res);
}