#include <cstdio>
using namespace std;

int main(){
	for ( int k; scanf( "%d", &k ) != -1 && k != 0; ) {
		int sum = 0;
		for ( int i = 0; i < k * ( k - 1 ) / 2; ++i ) {
			int n;
			scanf( "%d", &n );
			sum += n;
		}
		printf( "%d\n", sum / ( k - 1 ) );
	}
	return 0;
}