#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const long mod = 1e9 + 7;

int main(void) {
#ifdef DEBUG
  freopen("input.txt", "r", stdin);
#endif

  ios_base::sync_with_stdio(false);
  cin.tie(NULL);

  long R, G, B;
  cin >> R >> G >> B;

  vector<long> color = {R, G, B};
  sort(color.begin(), color.end());

  while (color[2] - color[0] > 2 &&
         color[2] - color[1] > 1 &&
         color[0] < color[1]) {
    color[0]++;
    color[2] -= 2;
  }
  while (1) {
    if (color[1] - color[0] < 2 && color[2] - color[1] > 3) {
      color[0] += 1;
      color[1] += 1;
      color[2] -= 4;
    } else if (color[1] - color[0] > 2) {
      color[0] += 2;
      color[1] -= 2;
      color[2] -= 2;
    }
    if (color[1] - color[0] < 3 && color[2] - color[1] < 3)
      break;
  }
  cout << min({color[0], color[1], color[2]}) << endl;
  return 0;
}