#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;
int main() {
int c, d;
char a[105], b[105];
string e="";
scanf("%s%s", a, b);
for(int i=0; i<strlen(a); i++) {
if(a[i]=='1') c=1;
else c=0;
if(b[i]=='1') d=1;
else d=0;
if(c^d) e+='1';
else e+='0';
}
printf("%s", e.c_str()); //http://stackoverflow.com/a/6419751/2948746
return 0;
}
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