#include <stdio.h>

#define MAX	32769

int ans[MAX];
int isprime[MAX];
int primes[MAX];
int num_primes;

int main(int argc, char *argv[])
{
	int i, j;
	int tmp, n;
	
	num_primes = 0;
	for (i = 2; i < MAX; i++) {
		if (isprime[i] == 0) {
			for (j = i+i; j < MAX; j+=i) {
				isprime[j] = 1;
			}

			primes[num_primes] = i;
			num_primes++;
		}
	}
	
	for (i = 0; i < num_primes; i++) {
		for (j = i; j < num_primes; j++) {
			tmp = primes[i] + primes[j];
			if (tmp < MAX) {
				ans[tmp]++;
			} else {
				break;
			}
		}
	}

	for (;;) {
		scanf("%d\n", &n);
		if (n == 0)
			break;
		printf("%d\n", ans[n]);
	}

	return 0;
}