#include <bits/stdc++.h>
using namespace std;
long long int ans(long long int r, long long int g, long long int b) {
  if (r == g && r == b && g == b) {
    return r;
  }
  long long int R(r % 3), G(g % 3), B(b % 3);
  long long int ans = (r / 3) + (b / 3) + (g / 3) + min(B, min(R, G));
  if ((R == 2 && B == 2 && G == 0 && g != 0) ||
      (G == 2 && B == 2 && R == 0 && r != 0) ||
      (G == 2 && R == 2 && B == 0 && b != 0)) {
    ans++;
  }
  return ans;
}
int main() {
  long long int r, g, b;
  cin >> r >> g >> b;
  cout << ans(r, g, b) << endl;
}
