#include <stdio.h>
int main (){
  int K,c[100],i,sum,SUM;
  while (1){
    scanf("%d",&K);
    if (K==0)break;
    sum=0;
    for (i=0;i<K*(K-1)/2;i++){
      scanf("%d",&c[i]);
      sum=sum+c[i];
    }
    SUM=sum/(K-1);
    printf("%d\n",SUM);
  }
  return 0;
}