#include <iostream>
using namespace std;

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