#include <bits/stdc++.h>
using namespace std;
int main() {
  long long z, t, r, b, i, j, m, c;
  long long a[3];
  cin >> z >> b >> t;
  a[0] = z;
  a[1] = b;
  a[2] = t;
  sort(a, a + 3);
  long long s1 = (a[1] / 3) + (a[2] / 3) + min(a[0], min(a[1] % 3, a[2] % 3)) +
                 ((a[0] - min(a[0], min(a[1] % 3, a[2] % 3))) / 3);
  a[1] = a[1] - a[0];
  a[2] = a[2] - a[0];
  long long s2 = a[0] + (a[1] / 3) + (a[2] / 3);
  cout << max(s1, s2);
  return 0;
}
