#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m, p, q, c, i, x, j, sum = 0, cnt = 0, ans, res;
  long long a[3];
  cin >> a[0] >> a[1] >> a[2];
  sort(a, a + 3);
  if (2 * (a[0] + a[1]) <= a[2])
    cout << a[0] + a[1] << endl;
  else if (a[1] > 0) {
    cout << (a[0] + a[1] + a[2]) / 3 << endl;
  } else
    cout << "0" << endl;
  return 0;
}
