#include <bits/stdc++.h>
using namespace std;
long long ans = 0, a, b, c;
void work(long long a, long long b, long long c) {
  if (b < c) swap(b, c);
  b -= c;
  a += c;
  if (b & 1)
    ans = max(ans, 1ll);
  else
    ans = max(ans, a);
}
int main() {
  scanf("%I64d%I64d%I64d", &a, &b, &c);
  work(a, b, c);
  work(b, a, c);
  work(c, a, b);
  printf("%I64d\n", a + b + c - ans);
}
