#include <bits/stdc++.h>
using namespace std;
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	long long N, K; cin >> N >> K; 
	long long mod = 998244353; 
	long long dp[65][65][2] = {}; 
	dp[0][0][0] = 1; 
	for(int i = 0; i <= 61; i++){
		if(!((N >> i) & 1) && !((K >> i) & 1)){
			for(int j = 0; j <= i+1; j++){
				dp[i+1][j][0] += dp[i][j][0]; 
				dp[i+1][j+1][0] += dp[i][j][1];
				dp[i+1][j][0] %= mod; dp[i+1][j+1][0] %= mod; 
			}
		}else if(!((N >> i) & 1) && ((K >> i) & 1)){
			for(int j = 0; j <= i+1; j++){
				dp[i+1][j+1][0] += dp[i][j][0]; 
				dp[i+1][j][1] += dp[i][j][1];
				dp[i+1][j+1][0] %= mod; dp[i+1][j][1] %= mod;
			}
		}else if(((N >> i) & 1) && !((K >> i) & 1)){
			for(int j = 0; j <= i+1; j++){
				dp[i+1][j][0] += dp[i][j][0]; 
				dp[i+1][j+1][0] += dp[i][j][0]; 
				dp[i+1][j+1][0] += dp[i][j][1];
				dp[i+1][j][1] += dp[i][j][1];
				dp[i+1][j][0] %= mod; dp[i+1][j+1][0] %= mod;
				dp[i+1][j][1] %= mod; 
			}
		}else if(((N >> i) & 1) && ((K >> i) & 1)){
			for(int j = 0; j <= i+1; j++){
				dp[i+1][j+1][0] += dp[i][j][0]; 
				dp[i+1][j][1] += dp[i][j][0]; 
				dp[i+1][j][1] += dp[i][j][1];
				dp[i+1][j+1][1] += dp[i][j][1];
				dp[i+1][j+1][0] %= mod; dp[i+1][j+1][1] %= mod;
				dp[i+1][j][1] %= mod; 
			}
		}
	}
	long long ans = 0; 
	for(int i = 0; i <= 61; i++){
		long long tmp1 = (1LL << i) % mod; 
		long long tmp2 = dp[62][i][0]; 
		ans += tmp1 * tmp2 % mod; 
	}
	cout << ans % mod << "\n"; 
}