// AOJ 1027: A Piece of Cake
// 2017.8.17 bal4u@uu
// 2017.12.15

#include <stdio.h>

char buf[20000], *p;

int getint()
{
	int n = 0;
	while (*p >= '0') n = (n<<3) + (n<<1) + (*p++ & 0xf);
	p++;
	return n;
}

int main()
{
	int K, i, s;
	
	while (fgets(p=buf, 10, stdin) && *p != '0') {
		K = getint();
		fgets(p=buf, sizeof(buf), stdin);
		s = 0, i = K*(K-1) >> 1; while (i--) s += getint();
		printf("%d\n", s / (K - 1));
	}
	return 0;
}