#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  long long r, g, b;
  cin >> r >> g >> b;
  long long ans = (r / 3) + (g / 3) + (b / 3);
  if (min({r, g, b}) > 0) {
    long long val = ((r - 1) / 3) + ((g - 1) / 3) + ((b - 1) / 3) + 1;
    ans = max(ans, val);
  }
  if (min({r, g, b}) > 1) {
    long long val = ((r - 2) / 3) + ((g - 2) / 3) + ((b - 2) / 3) + 2;
    ans = max(ans, val);
  }
  cout << ans << endl;
  return 0;
}
