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

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)

#define i64 int_fast64_t
const i64 INF = INT64_MAX;
const i64 ERR = INT64_MIN;
const i64 MOD = 998244353;

int main() {
  int A, B, ans2, ans10;
  string num;
  cin >> A >> B;
  ans2 = A+B;
  num = to_string(ans2);
  for(int i=0; i < num.size(); i++){
    if(num.at(i)=='2'){
      num.at(i) = '0';
    }
  }
  ans10=stoi(num, 0, 2);
  cout<< ans10 << endl;
}