// @rakibul-islam

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

using ll = long long;
const ll oo = 1e17;

int main() {
  cin.tie(0)->sync_with_stdio(0);
  int x, y, z;  cin >> x >> y >> z;
  if (x % 2 == y % 2) {
    cout << z << "\n";
  } else if (y % 2 == z % 2) {
    cout << x << "\n";
  } else {
    cout << y << "\n";
  }
  return 0;
}