#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, ans;
  cin >> a >> b >> c;
  int t = a / 3 + b / 3 + c / 3;
  int aa = a % 3;
  int bb = b % 3;
  int cc = c % 3;
  int x = aa + bb + cc;
  if (x >= 5)
    ans = t + x / 3;
  else if ((x == 3 || x == 4) && aa != 0 && bb != 0 && cc != 0)
    ans = t + x / 3;
  else
    ans = t;
  int xx = min(a, min(b, c));
  a = a - xx;
  b -= xx;
  c -= xx;
  if (a % 3 + b % 3 + c % 3 == 4 && xx) xx += 1;
  int d = a / 3 + b / 3 + c / 3 + xx;
  cout << max(ans, d);
}
