#include <stdio.h>

int main (){
  int K,c,i,sum;
  while (1){
    scanf("%d",&K);
    if (K==0)break;
    sum=0;
    for (i=0 ; i < (K*K-K)/2 ; i++){
      scanf("%d",&c);
      sum=sum+c;
    }
    printf("%d\n",sum/(K-1) );
  }
  
  return 0;
}