#include <bits/stdc++.h>
using namespace std;
const int INF = 100000000;
int main(){
  int R, G, B;
  cin >> R >> G >> B;
  int tv = 0;
  int fv = INF;
  while (fv - tv > 1){
    int mid = (tv + fv) / 2;
    int a = max(R - mid, 0) / 2 + max(G - mid, 0) / 2 + max(B - mid, 0) / 2;
    int b = max(mid - R, 0) + max(mid - G, 0) + max(mid - B, 0);
    if (a >= b){
      tv = mid;
    } else {
      fv = mid;
    }
  }
  cout << tv << endl;
}