#include <bits/stdc++.h>
using namespace std;
long long int hell = 1000000000;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int a[3];
  cin >> a[0] >> a[1] >> a[2];
  sort(a, a + 3);
  long long int p = 0, q = 0;
  q = hell;
  p = a[0] / 3 + a[2] / 3 + a[1] / 3;
  q = min(q, (a[0] % 3));
  q = min(q, (a[1] % 3));
  q = min(q, (a[2] % 3));
  p = p + q;
  if (a[0] > 0 && p > 0 && a[0] % 3 == 0 && a[1] % 3 == 2 && a[2] % 3 == 2) p++;
  if (p > 0 && a[1] % 3 == 0 && a[0] % 3 == 2 && a[2] % 3 == 2) p++;
  if (p > 0 && a[2] % 3 == 0 && a[1] % 3 == 2 && a[0] % 3 == 2) p++;
  cout << p;
  return 0;
}
