#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, b, c, s = 0;
  cin >> a >> b >> c;
  s += a / 3;
  s += b / 3;
  s += c / 3;
  if (a == 0 || b == 0 || c == 0) {
    cout << s;
    return 0;
  }
  a = a % 3;
  b = b % 3;
  c = c % 3;
  long long r = s;
  if (a % 3 == 0) {
    a += 3;
    s--;
  }
  if (b % 3 == 0) {
    b += 3;
    s--;
  }
  if (c % 3 == 0) {
    c += 3;
    s--;
  }
  s += min(a, min(b, c));
  cout << max(s, r);
  return 0;
}
