// AOJ 1027
#include<cstdio>

int main()
{
	int K, c;
	while( scanf( "%d", &K ), K )
	{
		int sum = 0;
		for( int i = 0; i != K*(K-1)/2; ++i )
		{
			scanf( "%d", &c );
			sum += c;
		}

		printf( "%d\n", sum / (K-1) );
	}

	return 0;
}