#include <bits/stdc++.h>
using namespace std;
long long a, b, c, ans;
long long solve(long long a, long long b, long long c) { return max(b, c); }
int main() {
  cin >> a >> b >> c;
  ans = 1LL << 62;
  if ((b & 1) == (c & 1)) ans = min(ans, solve(a, b, c));
  if ((c & 1) == (a & 1)) ans = min(ans, solve(b, c, a));
  if ((a & 1) == (b & 1)) ans = min(ans, solve(c, a, b));
  cout << ans << endl;
  return 0;
}
