#include <stdio.h>
#include <stdint.h>
#include <math.h>

int main() {
	unsigned long a, b, ans;
	unsigned long res[32];
	scanf("%lu %lu", a, b);

	for (int i = 1; i < 32; i++) {	
		res[i-1] = (a+b) % (unsigned int)pow(10, i) / (unsigned int)pow(10, i-1);
		if (res[i-1] == 2) {
			res[i-1] = 0;
		}
	}
	
	for (int i = 0; i < sizeof(res); i++) {
		ans += pow(2, i) * res[i];
	}
	printf("%d\n", ans);
	
	return 0;
}