#include <bits/stdc++.h>
using namespace std;
long long a, b, c;
long long data[5];
int main() {
  long long ans = 10000000000;
  while (cin >> a >> b >> c) {
    if ((a + b) % 2 == 0) ans = min(ans, max(a, b));
    if ((a + c) % 2 == 0) ans = min(ans, max(a, c));
    if ((c + b) % 2 == 0) ans = min(ans, max(c, b));
    cout << ans << endl;
  }
}
