#include <bits/stdc++.h>
using namespace std;
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cout << name << " : " << arg1 << "\n";
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cout.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}
void bolt() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
int32_t main() {
  bolt();
  long long r, g, b;
  cin >> r >> g >> b;
  vector<long long> a = {r, g, b};
  sort(a.begin(), a.end());
  if (a[1] == 0) {
    cout << 0;
    return 0;
  }
  if (a[0] + a[1] <= a[2] / 2) {
    cout << a[0] + a[1];
    return 0;
  }
  cout << (a[0] + a[1] + a[2]) / 3;
  return 0;
}
