#include <iostream>
#include <string>
using namespace std;
//逐个对比,合成新整数
int combine(string n, int dn){
int temp = 0;
for (int i = 0; i < n.length(); i++) {
if (n[i] - '0' == dn) {
temp = temp * 10 + dn;
}
}
return temp;
}
int main(){
string a, b;
int da,db;
cin >> a >> da >> b >> db;
cout << combine(a,da) + combine(b,db);
return 0;
}