#include <iostream>
#include <math.h>
#include <algorithm>
using namespace std;

int main() {
  int a[3];
  for (int i = 0; i < 3; i++) {
    cin >> a[i];
  }
  sort(a, a + 3);

  while (a[0] + 2 <= a[2]) {
    a[0] += 1;
    a[2] -= 2;
    sort(a, a + 3);
  }

  cout << min({ a[0],a[1],a[2] }) << endl;

  return 0;
}