#include <stdio.h>

long long int cnt(int x) {
	return 1 << (x - 1);
}

int main() {
	int a, b;
	scanf("%d%d", &a, &b);
	if ((a & b) != a) printf("0\n");
	else printf("%lld\n", cnt(__builtin_popcount(a ^ b)));
}