#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
const int N = 2e5 + 3;
const int MOD = 998244353;
int max1 = 0, max2 = 0;
void solve() {
  long long int a[3];
  cin >> a[0] >> a[1] >> a[2];
  sort(a, a + 3);
  cout << (a[0] + a[1] + min(a[2], 2 * (a[1] + a[0]))) / 3 << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t = 1;
  while (t--) {
    solve();
  }
}
