#include <bits/stdc++.h>
using namespace std;
template <class T>
inline void read(T& x) {
  bool fu = 0;
  char c;
  for (c = getchar(); c <= 32; c = getchar())
    ;
  if (c == '-') fu = 1, c = getchar();
  for (x = 0; c > 32; c = getchar()) x = x * 10 + c - '0';
  if (fu) x = -x;
};
template <class T>
inline void read(T& x, T& y) {
  read(x);
  read(y);
}
template <class T>
inline void read(T& x, T& y, T& z) {
  read(x);
  read(y);
  read(z);
}
long long a[5];
int main() {
  for (int i = 1; i <= 3; ++i) read(a[i]);
  sort(a + 1, a + 3 + 1);
  if ((a[1] + a[2]) * 2 < a[3])
    cout << a[1] + a[2] << endl;
  else
    cout << (a[1] + a[2] + a[3]) / 3 << endl;
  return 0;
}
