#include <iostream>
using namespace std;
int main(){
  int k,s,c,i;
  while(1){
    cin >>k;
    if (!k) break;
    for(i=0,s=0;i<k*(k-1)/2;i++)
      cin>>c,s+=c;
    cout <<s/(k-1)<<endl;   
  }
  return 0;
}