#include <bits/stdc++.h>
using namespace std;
int main() {
  int r, g, b, ans = 0;
  cin >> r >> g >> b;
  int mix0 = 0, mix1 = 0, mix2 = 0;
  mix0 = r / 3 + g / 3 + b / 3;
  if (r > 0 && g > 0 && b > 0)
    mix1 = 1 + (r - 1) / 3 + (g - 1) / 3 + (b - 1) / 3;
  if (r > 1 && g > 1 && b > 1)
    mix2 = 2 + (r - 2) / 3 + (g - 2) / 3 + (b - 2) / 3;
  if (mix0 < mix1)
    ans = (mix1 > mix2) ? mix1 : mix2;
  else
    ans = (mix0 > mix2) ? mix0 : mix2;
  cout << ans;
  return 0;
}
