#include <bits/stdc++.h>
using namespace std;
int ans;
int solve(int a, int b) {
  int maxi = max(a, b), mini = min(a, b);
  if (maxi + mini < 3) return 0;
  if (2 * mini <= maxi)
    return mini;
  else
    return (mini + maxi) / 3;
}
int main() {
  long long s[3];
  cin >> s[0] >> s[1] >> s[2];
  sort(s, s + 3);
  cout << min((s[0] + s[1] + s[2]) / 3, s[0] + s[1]) << endl;
  return 0;
}
