#include <bits/stdc++.h>
using namespace std;
string s1[1001];
long long r, g, b, t1, t2, t3, ans;
map<string, int> mp, tp;
int main() {
  cin >> r >> g >> b;
  if (r != 0 && g != 0 && b != 0) {
    t1 = r % 3;
    t2 = g % 3;
    t3 = b % 3;
  }
  if (t1 != 0 && t2 != 0 && t3 == 0)
    t3 = 3;
  else if (t1 != 0 && t3 != 0 && t2 == 0)
    t2 = 3;
  else if (t2 != 0 && t3 != 0 && t1 == 0)
    t1 = 3;
  while (t1 > 0 && t2 > 0 && t3 > 0) {
    ans++;
    t1--;
    t2--;
    t3--;
  }
  r -= t1;
  g -= t2;
  b -= t3;
  ans += (r / 3 + g / 3 + b / 3);
  cout << ans;
}
