#include<stdio.h>

int main(void){
    int n,i,a,s;
    while(scanf("%d",&n) , n != 0){
        s = 0;
        for(i = 1;i <= n * (n - 1) / 2;i++){
            scanf("%d",&a);
            s+=a;
        }
        printf("%d\n" , s / (n - 1));
    }
    return 0;
}