#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <fstream>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>
#include <numeric>
#include <iterator>

typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;

ll gcd(ll a, ll b) {
    if (a < b)swap(a, b);
    if (b == 0)return a;
    return gcd(b, a % b);
}
int lcm(int a, int b) {
    return a * b / gcd(a, b);
}




int main()
{

    int Q;
    Q = 1;
    //cin >> Q;   

    while (Q--) {
        int a, b;
        cin >> a >> b;
        int ans = 0;
        
        for (int i = 0; i <= b; i++) {
            int t = a, x = i;
            bool f = 1;
            for (int j = 0; j < 11; j++) {
                if (1 << j & b) {
                    if (1 << j & i|| 1 << j & a)continue;
                    f = 0;
                }
                else {
                    if (1 << j & i || 1 << j & a)f=0;
                }
            }
            if (f)ans++;
            
        }
        cout << ans;
    }
        return 0;
}