#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  ll a, b, c, t, ans = -1, d;
  cin >> a >> b >> c;
  d = min(a, min(b, c));
  for (int i = 0; i < 3; i++) {
    if (d < i) break;
    t = (a - i) / 3 + (b - i) / 3 + (c - i) / 3 + i;
    if (t > ans) ans = t;
  }
  cout << ans;
  return 0;
}
