#include <iostream>
using namespace std;

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