#include <bits/stdc++.h>
using namespace std;
int main() {
  long long color[3];
  while (cin >> color[0] >> color[1] >> color[2]) {
    sort(color, color + 3);
    if (color[2] / 2 >= (color[0] + color[1]))
      cout << color[0] + color[1] << endl;
    else
      cout << (color[0] + color[1] + color[2]) / 3 << endl;
  }
  return 0;
}
