#include <bits/stdc++.h>
using namespace std;
int a, b, c;
int main() {
  cin >> a >> b >> c;
  int a0 = a, b0 = b, c0 = c;
  int ans = a / 3 + b / 3 + c / 3;
  a %= 3;
  b %= 3;
  c %= 3;
  int t = min(min(a, b), c);
  a -= t;
  b -= t;
  c -= t;
  ans += t;
  if (a + b + c == 4)
    if (min(min(a0, b0), c0)) ans++;
  cout << ans << endl;
  return 0;
}
