#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  int r, g, b, aux, ret = 0;
  cin >> r >> g >> b;
  int mn = min(r % 3, min(g % 3, b % 3));
  if (r && g && b && (r % 3 + g % 3 + b % 3 == 4) && mn == 0) {
    r -= 2;
    g -= 2;
    b -= 2;
    ret += 2;
  }
  ret += r / 3 + g / 3 + b / 3;
  r = r % 3;
  g = g % 3;
  b = b % 3;
  while (r > 0 && g > 0 && b > 0) {
    ret++;
    r--;
    g--;
    b--;
  }
  cout << ret << endl;
  return 0;
}
