#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());
  if (color[2] > 2 && color[2] - 1 > color[1]) {
    long n = (color[2] - color[1]) / 2;
    color[0] += n;
    color[2] -= n * 2;
  }
  if (color[2] > 2 && color[2] - 1 > color[0]) {
      long n = (color[1] - color[0] + 4 - 1) / 4;
      color[0] += n;
      color[2] -= n * 2;
  }
  if (color[1] > 2 && color[1] - 1 > color[0]) {
    long n = (color[1] - color[0]) / 2;
    color[0] += n;
    color[1] -= n * 2;
  }
  cout << min({color[0], color[1], color[2]}) << endl;
  return 0;
}