#include <iostream>

using namespace std;

int a,b,num,cif1,cif2,med, z=1;

int main()

{

   cin >> a >> b;

   while (a!=0)

   {

       cif1=a%10; cif2=b%10;

       med=(cif1+cif2)/2;

       a=a/10; b=b/10;

       num=med*z+num;

       z=z*10;

   }

   cout << num;

}