#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

int main(){
  vector<int> RGB(3, 0);
  for(int i = 0; i < 3; i++){
    cin >> RGB[i];
  }
  for(int i = 0; i <= 10000001; i++){
    int now = 0;
    for(int j = 0; j < 3; j++){
      if(i <= RGB[j]) now += (RGB[j]-i)/2;
      else now -= (i - RGB[j]);
    }
    if(now < 0){
      cout << i-1 << endl;
      return 0;
    }
  }
}