#include <iostream>

using namespace std;

int main(){
  int num,pair,sum;
  while(cin >> num && num != 0){
    sum = 0;
    for(int i=0;i<num*(num-1)/2;i++){

      cin >> pair;
      sum += pair;
    //    cout << hairetsu[i][0] << " " << hairetsu[i][1];
    //    cout << endl;
    }
    sum /= num - 1;
    
    cout << sum << endl;
  }
  
  
}