#include <iostream>
#include <algorithm>
using namespace std;

int main(){
   int rgb[3];
   cin >> rgb[0] >> rgb[1] >> rgb[2];
   while(true){
      stable_sort(rgb,rgb + 3);
      if(rgb[0] + 3 > rgb[2]) break;
      rgb[0]++;
      rgb[2] -= 2;
   }
   cout << rgb[0] << endl;
}