#include <bits/stdc++.h>
using namespace std;
bool IsPrime(long long x) {
  bool isPrime = true;
  for (long long a = 2; a * a <= x; a++) {
    if (x % a == 0) return false;
  }
  return true;
}
long long A[1000010], B[1000010], C[200002];
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long a, b, c, m, d;
  cin >> a >> b >> c;
  if (a % 3 == 0 && b % 3 == 0 && c % 3 == 0) {
    cout << a / 3 + b / 3 + c / 3;
    return 0;
  }
  a--;
  b--;
  c--;
  d = a / 3 + b / 3 + c / 3;
  a %= 3;
  b %= 3;
  c %= 3;
  a++;
  b++;
  c++;
  if (a == b && b == c) {
    cout << (a + b + c) / 3 + d;
    return 0;
  }
  m = min(a, b);
  m = min(c, m);
  long long mm = max(a, b);
  mm = max(c, mm);
  if (m == 2) {
    cout << d + 2;
    return 0;
  }
  if ((m == 1 && mm == 3) || m == 0) {
    cout << a / 3 + b / 3 + c / 3 + d;
    return 0;
  }
  if (m == 1 && mm == 2) cout << d + 1;
}
