#include <bits/stdc++.h>
using namespace std;
int main() {
 int x,y,z;
 cin>>x>>y>>z;
 if((x+y)%2==0){
     cout<<z<<endl;
 }
 else if((y+z)%2==0){
     cout<<x<<endl;
 }
 else if((z+x)%2==0){
     cout<<y<<endl;
 }
}