#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[3];
  long long ctr = 0;
  for (int i = 0; i < 3; i++) {
    cin >> a[i];
  }
  long long zeroMixed = 0;
  for (int i = 0; i < 3; i++) {
    zeroMixed += (a[i] / 3);
  }
  sort(a, a + 3);
  long long oneMixed = -1;
  if (a[0] >= 1) {
    oneMixed = 1;
    for (int i = 0; i < 3; i++) {
      oneMixed += ((a[i] - 1) / 3);
    }
  }
  long long twoMixed = -1;
  if (a[0] >= 2) {
    twoMixed = 2;
    for (int i = 0; i < 3; i++) {
      twoMixed += ((a[i] - 2) / 3);
    }
  }
  cout << max(twoMixed, max(oneMixed, zeroMixed));
  return 0;
}
