#include<iostream>
#include<algorithm>

using namespace std;

int x, n;

int main(){
	while(cin >> n, n){
		int res = 0;
		for(int i = 0;i < n *(n-1)/2;i++){
			cin >> x;
			res += x;
		}
		cout << res / (n-1) << endl;
	}                               
	return 0;
}