#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, b, c;
  cin >> a >> b >> c;
  if (a <= b) {
    swap(a, b);
  }
  if (a <= c) {
    swap(a, c);
  }
  if (b <= c) {
    swap(b, c);
  }
  if ((b + c) % 2 == 0) {
    cout << b;
  } else {
    cout << a;
  }
  return 0;
}
