#include <bits/stdc++.h>
using namespace std;
int main() {
  long long r, g, b;
  cin >> r >> g >> b;
  long long a[3];
  a[0] = g;
  a[1] = b;
  a[2] = r;
  sort(a, a + 3);
  cout << min(a[0] + a[1], (g + r + b) / 3);
  return 0;
}
