#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int r, g, b, res = 0, flag = 0, sum;
  cin >> r;
  cin >> g;
  cin >> b;
  sum = r + g + b;
  if (r == 0 || g == 0 || b == 0) {
    cout << r / 3 + g / 3 + b / 3;
    return 0;
  } else if (r % 3 != g % 3 && r % 3 != b % 3 && b % 3 != g % 3) {
    if (r < b && r < g) {
      cout << r + (g - r) / 3 + (b - r) / 3;
      return 0;
    } else if (b < g) {
      cout << b + (g - b) / 3 + (r - b) / 3;
      return 0;
    } else {
      cout << g + (r - g) / 3 + (b - g) / 3;
      return 0;
    }
  } else {
    cout << sum / 3;
    return 0;
  }
  return 0;
}
