#include <bits/stdc++.h>
using namespace std;
template <typename T>
T maxm(T a, T b) {
  return (a > b) ? a : b;
}
template <typename T>
T minm(T a, T b) {
  return (a < b) ? a : b;
}
template <typename T>
T powe(T e, T n) {
  T x = 1, p = e;
  while (n) {
    if (n & 1) x = x * p;
    p = p * p;
    n >>= 1;
  }
  return x;
}
template <typename T>
T power(T e, T n, T m) {
  T x = 1, p = e;
  while (n) {
    if (n & 1) x = (x * p) % m;
    p = (p * p) % m;
    n >>= 1;
  }
  return x;
}
template <typename T>
T InverseEuler(T a, T m) {
  return (a == 1 ? 1 : power(a, m - 2, m));
}
template <typename T>
T lcm(T a, T b) {
  return (a * (b / __gcd(a, b)));
}
long long MAX = (long long)(3 * 1e18);
long long MOD = (long long)(1e9 + 7);
using std::cin;
using std::cout;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ;
  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 {
    cout << (a[1] + a[0] + a[2]) / 3 << endl;
  }
  return 0;
}
