#include<bits/stdc++.h>
#define eb emplace_back
#define ep emplace
using namespace std;

using ll = long long;
constexpr int mod = 998244353;


using T = array<array<ll, 3>, 3>;

T operator * (T a, T b) {
	T c;
	for(int i = 0; i < 3; ++ i) {
		for(int j = 0; j < 3; ++ j) {
			c[i][j] = 0;
			for(int k = 0; k < 3; ++ k) {
				c[i][j] = (c[i][j] + a[i][k] * b[k][j]) % mod;
			}
		}
	}
	return c;
}
T qpow(T a, int b) {
	T c;
	for(int i = 0; i < 3; ++ i) {
		for(int j = 0; j < 3; ++ j) {
			c[i][j] = i == j;
		}
	}
	while(b) {
		if(b & 1) c = c * a;
		b >>= 1;
		a = a * a;
	}
	return c;
}
int n, m; ll f[31][2];

main() {
	scanf("%d%d", &n, &m);
	if(!m) {
		puts("1");
		exit(0);
	}
	T a = qpow({{{0, 1, 1}, {1, 0, 0}, {0, 1, 0}}}, n - 1);
	ll coef = (3 * a[2][0] + 2 * a[2][1]) % mod;
	int lim = __lg(m);
	if(m & 1) {
		f[0][0] = coef;
	}
	else {
		f[0][0] = f[0][1] = 1;
	}
	for(int k = 1; k <= lim; ++ k) {
		if(m >> k & 1) {
			f[k][0] = (f[k - 1][0] * coef + f[k - 1][1]) % mod; 
			f[k][1] = f[k - 1][1];
		}
		else {
			f[k][0] = f[k - 1][0]; 
			f[k][1] = (f[k - 1][1] * coef + f[k - 1][0]) % mod;
		}
	}
	printf("%lld", f[lim][0]);
}