#include<iostream>

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