#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, b, c;
  cin >> a >> b >> c;
  vector<long long> v, z;
  v.push_back(a);
  v.push_back(b);
  v.push_back(c);
  sort(v.begin(), v.end());
  long long cnt = a / 3;
  a = a % 3;
  cnt = cnt + b / 3;
  b = b % 3;
  cnt = cnt + c / 3;
  c = c % 3;
  long long x = min(a, (min(b, c)));
  cnt = cnt + x;
  a = a - x;
  b = b - x;
  c = c - x;
  z.push_back(a);
  z.push_back(b);
  z.push_back(c);
  sort(z.begin(), z.end());
  if (z[0] == 0 && z[1] == 2 && z[2] == 2 && v[0] != 0) cnt++;
  cout << cnt;
}
