#include <iostream>

using namespace std;

int main()
{
  int k;
  int c;
  int sum;

  while (cin >> k && k != 0){
    int i = (k * (k - 1)) / 2;
    sum = 0;
    while (i--){
      cin >> c;
      sum += c;
    }
    cout << sum / (k - 1) << endl;
  }
}