#include <bits/stdc++.h>
using namespace std;
int main() {
  long long r, g, b;
  cin >> r >> g >> b;
  long long ans = min(r, min(g, b));
  long long mini = ans;
  if (r <= 3 && g <= 3 && b <= 3) {
    cout << ans << endl;
    return 0;
  }
  long long count = 0;
  r = r - ans;
  g = g - ans;
  b = b - ans;
  if (r % 3 == 2) {
    ++count;
  }
  if (g % 3 == 2) {
    ++count;
  }
  if (b % 3 == 2) {
    ++count;
  }
  ans += (r / 3) + (g / 3) + (b / 3);
  if (count == 2 && mini != 0) {
    ++ans;
  }
  cout << ans << endl;
}
