#include <bits/stdc++.h>
using namespace std;
long long a[3], res;
int main() {
  cin >> a[0] >> a[1] >> a[2];
  sort(a, a + 3);
  res = (long long)1e10;
  for (int i = 0; i < 3; i++)
    for (int j = 0; j < 3; j++)
      if (a[i] % 2 == a[j] % 2 && i != j) res = min(res, max(a[i], a[j]));
  cout << res << endl;
  return 0;
}
