#include<iostream>
using namespace std;
 
int main(){

  int k;

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