#include<stdio.h>
int k;
int c[10000];
int main(){
  int i;
  int sum;
  while(scanf("%d",&k), k != 0){
    for(i = 0; i < k*(k-1)/2; i++){
      scanf("%d",&c[i]);
    }
    sum = 0;
    for(i = 0; i < k*(k-1)/2; i++){
      sum += c[i];
    }
    sum = sum/(k-1);
    
    printf("%d\n",sum);
  }
  return 0;   
}