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

#define int long long

#ifdef DEBUG
#include<algo/debug.h>
#include<algo/resources.h>
#else
#   define clog if (0) cerr
#   define DB(...)
#   define db(...) "" 
#endif

const int M = 1e9 + 7;
const int N = 2e5 + 10;


int32_t main(){
  int a, b, c;
  cin >> a >> b >> c;
  if(a % 2 != b % 2 and a % 2!= c % 2)cout << a << endl;
  if(b % 2 != c % 2 and b % 2!= a % 2)cout << b << endl;
  if(c % 2 != a % 2 and c % 2!= b % 2)cout << c << endl; 
}