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