#include <iostream>
#include <algorithm>

using namespace std;

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

	return 0;
}