61A

#include <stdio.h>
#include <string.h>
 
#define Maxsize 110
 
int main()
{
	char line1[Maxsize];
	char line2[Maxsize];
	scanf("%s", line1);
	scanf("%s", line2);
	int length=strlen(line1);
	int i;
	for(i=0; i<length; ++i)
	{
		if(line1[i]==line2[i])
			printf("%c", '0');
		else
			printf("%c", '1');
	}
	printf("\n");
	return 0;
}