#include <bits/stdc++.h>
using namespace std;
template <class T1>
void deb(T1 e) {
  cout << "-->" << e << endl;
}
template <class T1, class T2>
void deb(T1 e1, T2 e2) {
  cout << "-->" << e1 << " " << e2 << endl;
}
template <class T1, class T2, class T3>
void deb(T1 e1, T2 e2, T3 e3) {
  cout << "-->" << e1 << " " << e2 << " " << e3 << endl;
}
template <class T1, class T2, class T3, class T4>
void deb(T1 e1, T2 e2, T3 e3, T4 e4) {
  cout << "-->" << e1 << " " << e2 << " " << e3 << " " << e4 << endl;
}
template <class T1, class T2, class T3, class T4, class T5>
void deb(T1 e1, T2 e2, T3 e3, T4 e4, T5 e5) {
  cout << "-->" << e1 << " " << e2 << " " << e3 << " " << e4 << " " << e5
       << endl;
}
template <class T1, class T2, class T3, class T4, class T5, class T6>
void deb(T1 e1, T2 e2, T3 e3, T4 e4, T5 e5, T6 e6) {
  cout << "-->" << e1 << " " << e2 << " " << e3 << " " << e4 << " " << e5 << " "
       << e6 << endl;
}
int main() {
  long long a[5];
  while (scanf("%lld %lld %lld", &a[0], &a[1], &a[2]) == 3) {
    sort(a, a + 3);
    printf("%lld\n", !((a[0] + a[1]) % 2) ? a[1] : a[2]);
  }
  return 0;
}
