#include <iostream>
#include <string>
using namespace std;
int main(){
string str_a, str_b;
while(cin >> str_a){
str_b = str_a;
int x = str_a.length() - 1;
for(int i = 0; i < str_a.length(); i++){
cout << int(str_a[i] - 48) + (int(str_b[x]) - 48);
x -= 1;
}
cout << '\n';
}
return 0;
}