61A

#include<bits/stdc++.h>
using namespace std;
int main()
{
    long long int n,i,j,k,m,l;
    string s1,s2,result,re;
    cin>>n>>m;
    while(n)
    {
        k=n%10;
        l=m%10;
        s1+=(k+'0');
        s2+=(l+'0');
        n=n/10;
        m=m/10;
    }
    result ="";
    for(i=0; i<s1.length(); i++)
    {
        if(s1[i]==s2[i])
        {
            result += "0";
        }
        else
        {
            result +="1";
        }
    }
    re="";
    for(j=result.length(); j>=0; j--)
    {
        re+=result[j];
    }

    cout<<re<<endl;

    return 0;

}