#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <algorithm>
#include <sstream>
#include <map>
#include <set>

#define REP(i,k,n) for(int i=k;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)
#define INF 1<<30
#define pb push_back
#define mp make_pair

using namespace std;
typedef long long ll;
typedef pair<int,int> P;

int main() {
	int n;
	while(cin >> n && n) {
		int m = n * (n-1) / 2;
		vector<int> v(m);
		rep(i,m) cin >> v[i];

		int sum = 0;
		rep(i,m) {
			sum += v[i];
		}

		cout << sum / (n-1) << endl;
	}


	return 0;
}