#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  long long a, b, c;
  cin >> a >> b >> c;
  long long mod1 = a % 3;
  long long mod2 = b % 3;
  long long mod3 = c % 3;
  long long total = 0;
  if (a < 3 && b < 3 && c < 3) {
    total = 0;
  } else if (mod1 == mod2 && mod1 == mod3 && mod2 == mod3) {
    total += mod1;
    a -= mod1;
    b -= mod1;
    c -= mod1;
    total += a / 3 + b / 3 + c / 3;
  } else if (mod1 == mod2) {
    if (a >= 3 && b >= 3 && c >= 3) {
      total += mod1;
      a -= mod1;
      b -= mod1;
      c -= mod1;
    }
    total += a / 3 + b / 3 + c / 3;
  } else if (mod2 == mod3) {
    if (a >= 3 && b >= 3 && c >= 3) {
      total += mod2;
      a -= mod2;
      b -= mod2;
      c -= mod2;
    }
    total += (a / 3 + b / 3 + c / 3);
  } else if (mod1 == mod3) {
    if (a >= 3 && b >= 3 && c >= 3) {
      total += mod1;
      a -= mod1;
      b -= mod1;
      c -= mod1;
    }
    total += a / 3 + b / 3 + c / 3;
  } else {
    total += a / 3 + b / 3 + c / 3;
  }
  cout << total << endl;
  return 0;
}
