#include <bits/stdc++.h>
using namespace std;
int main() {
  int r, b, g;
  cin >> r >> b >> g;
  int count = (r % 3);
  count += (g % 3);
  count += (b % 3);
  int ans;
  if (count == 4) {
    ans = (r / 3) + (g / 3) + (b / 3);
    if (min(r, min(g, b)) != 0) ans += 1;
  } else {
    ans = (r / 3) + (g / 3) + (b / 3);
    int l = min((r % 3), min((g % 3), (b % 3)));
    ans += l;
  }
  cout << ans;
}
