#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<long long> mass(3);
  cin >> mass[0] >> mass[1] >> mass[2];
  sort(mass.begin(), mass.end());
  long long ans = 0;
  long long a = mass[1] + mass[0];
  long long b = mass[2];
  if (b < 2 * a) {
    ans += (a + b) / 3;
  } else {
    ans += a;
  }
  cout << ans;
}
