#include <bits/stdc++.h>
using namespace std;
int main() {
  int r, g, b;
  cin >> r >> g >> b;
  int ans = 0;
  ans = r / 3 + g / 3 + b / 3;
  if (min(r, min(g, b)) >= 1)
    ans = max(ans, (r - 1) / 3 + (g - 1) / 3 + (b - 1) / 3 + 1);
  if (min(r, min(g, b)) >= 2)
    ans = max(ans, (r - 2) / 3 + (g - 2) / 3 + (b - 2) / 3 + 2);
  cout << ans;
}
