#include <iostream>
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 c;
			cin >> c;
			sum += c;
		}
		cout << sum / (K - 1) << endl;
	}
	return 0;
}