#include <bits/stdc++.h>
using namespace std;
const int n = 1e7;
int main() {
  long long a, b, c, ans = 0;
  cin >> a >> b >> c;
  long long mx = max(a, max(b, c));
  long long sum = (a + b + c) - mx;
  if (sum * 2 <= mx)
    cout << sum << endl;
  else
    cout << (a + b + c) / 3 << endl;
}
