#include <bits/stdc++.h>
using namespace std;
long long a, b, c;
long long wyn;
int main() {
  wyn = 1000000000;
  wyn *= wyn;
  scanf("%lld%lld%lld", &a, &b, &c);
  if ((a & 1) == (b & 1)) wyn = min(wyn, max(a, b));
  if ((a & 1) == (c & 1)) wyn = min(wyn, max(a, c));
  if ((c & 1) == (b & 1)) wyn = min(wyn, max(c, b));
  printf("%lld\n", wyn);
  return 0;
}
