#include<bits/stdc++.h>

const int mod = 998244353;

int add(int a, int b) {
	return a + b >= mod ? a + b - mod : a + b;
} 
int sub(int a, int b) {
	return a >= b ? a - b : a + mod - b;
}
int mul(int a, int b) {
	return 1ll * a * b % mod;
}
int power(int a, int b) {
	int res = 1;
	for (; b; b >>= 1, a = mul(a, a)) if (b & 1) res = mul(res, a);
		return res;
}
int inv(int x) {
	return x == 1 ? 1 : sub(0, mul(mod / x, inv(mod % x)));
}

std::vector<std::vector<int>> mul(std::vector<std::vector<int>> a,
									std::vector<std::vector<int>> b) {
	int n = a.size();
	int m = a[0].size();
	int k = b[0].size();
	std::vector c(n, std::vector(k, 0));
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < m; ++j) {
			for (int l = 0; l < k; ++l) {
				c[i][l] = add(c[i][l], mul(a[i][j], b[j][l]));
			}
		}
	}
	return c;
}

std::vector<std::vector<int>> power(std::vector<std::vector<int>> a, int b) {
	int n = a.size();
	std::vector ret(n, std::vector(n, 0));
	for (int i = 0; i < n;  ++i) ret[i][i] = 1;
	for (; b; b >>= 1, a = mul(a, a)) if (b & 1) ret = mul(ret, a);
	return ret;
}

int main() {
	std::cin.tie(nullptr)->sync_with_stdio(false);

	int n, m;
	std::cin >> n >> m;
	std::vector cal(4, std::vector(4, 0));
	for (int i = 0; i < 4; ++i) {
		for (int z = 0; z < 2; ++z) {
			int x = i & 1, y = i >> 1;
			if ((x & z) + y == 1) {
				cal[i][i / 2 + z * 2] = 1;
			}
		}
	}
	int shusha = 0;
	for (int c = 0; c < 4; ++c) {
		std::vector sheesh(1, std::vector(4, 0));
		sheesh[0][c] = 1;
		sheesh = mul(sheesh, power(cal, n - 2));
		for (int i = 0; i < 4; ++i) {
			int x = i & 1, y = i >> 1, z = c & 1, l = c >> 1;
			if ((x & z) + y == 1 && (y & l) + z == 1) shusha = add(shusha, sheesh[0][i]);
		}
	}
	std::array<int, 2> dp;
	dp[0] = 1;
	dp[1] = 0;
	for (int i = 0; i <= 30; ++i) {
		std::array<int, 2> nw = {0, 0};
		for (int x = 0; x < 2; ++x) {
			int c = (m >> i & 1) - x;
			for (int q = 0; q <= 2; ++q) {
				int v;
				if (q == 1) v = shusha;
				else v = 1;
				int y = c - q;
				// std::cout << i << ' ' << x << ' ' << q << ' ' << y << ' ' << v << ' ' << dp[x] << std::endl;
				if (y % 2 != 0) continue;
				y = -y / 2;
				nw[y] = add(nw[y], mul(v, dp[x]));
			}
		}
		dp = nw;
		// std::cout << dp[0] << ' ' << dp[1] << std::endl;
	}
	std::cout << dp[0];
}