#include <bits/stdc++.h>
using namespace std;

int main() {
  long long a, b;
  cin >> a >> b;
  long long c = a+b;
  
  string s = to_string(c);
  reverse(s.begin(), s.end());
  
  long long N = s.size();
  for(long long i=0; i<N; i++){
    if(s[i] == '2') {
      c -= pow(10, i);
      c -= pow(10, i);
    }
  }
  
  long long binary = c;
  long long decimal = 0;
  long long base = 1;
  while(binary>0){
    decimal = decimal + ( binary % 10 ) * base;
    binary = binary / 10;
    base = base * 2;
  }

  cout << decimal << endl;
}