#include <bits/stdc++.h>
using namespace std;
void Solve() {
  long long a[3];
  cin >> a[0] >> a[1] >> a[2];
  sort(a, a + 3);
  if ((a[0] + a[1]) * 2 <= a[2]) {
    cout << a[0] + a[1];
  } else {
    cout << (a[0] + a[1] + a[2]) / 3;
  }
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  Solve();
  return 0;
}
