#include <bits/stdc++.h>
using namespace std;
int a, b, c, n, m, k, x, y, z, o, p, ans;
int main() {
  cin >> a >> b >> c;
  x = a;
  y = b;
  z = c;
  m += a / 3;
  a = a % 3;
  m += b / 3;
  b = b % 3;
  m += c / 3;
  c = c % 3;
  m += min(a, min(b, c));
  if (x > 0 && y > 0 && z > 0) {
    a = x;
    b = y;
    c = z;
    a--;
    b--;
    c--;
    n++;
    n += a / 3;
    a = a % 3;
    n += b / 3;
    b = b % 3;
    n += c / 3;
    c = c % 3;
    n += min(a, min(b, c));
  }
  cout << max(n, m);
}
