#include <bits/stdc++.h>
long long int mod = 998244353;
long long int inf = 1000000000000000000;
using namespace std;
mt19937 unlucko(chrono::steady_clock::now().time_since_epoch().count());
int main() {
  iostream::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long int a, b, c;
  cin >> a >> b >> c;
  long long int ans = (1LL << 31);
  if (abs(a - b) % 2 == 0) ans = min(max(a, b), ans);
  if (abs(a - c) % 2 == 0) ans = min(max(a, c), ans);
  if (abs(c - b) % 2 == 0) ans = min(max(c, b), ans);
  cout << ans;
}
