bool prime(int x) {
	if (x <= 1)return false;
	for (int i = 2; i <= sqrt(x); i++)
		if (x % i == 0)return false;
	return true;
}

int sieve(int x) {
	for (int i = 0; i <= x; i++)vis[i] = false;//初始化
	for (int i = 2; i * i <= x; i++)//筛掉非素数
		if (!vis[i])
			for (int j = i * i; j <= x; j += i)
				vis[j] = true;
	int k = 0;
	for (int i = 2; i <= x; i++)//统计素数
		if (!vis[i])
			prime[k++] = i;
	return k;//返回[1,x]内素数个数
}

#include<bits/stdc++.h>
using namespace std;
bool prime(int x) {
	if (x <= 1)return false;
	for (int i = 2; i <= sqrt(x); i++)
		if (x % i == 0)return false;
	return true;
}
int main() {
	int m;
	while (cin >> m) {
		int a = m / 2;
		if (a % 2 == 0)a--;
		int b = m - a;
		while (prime(a)==false||prime(b)==false) {
			a -= 2;
			b += 2;
		}
		cout << a << " " << b << "n";
	}
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
const int maxn = 100005;
int n, vis[maxn], ans[maxn];
void sieve() {
	memset(vis, 0, sizeof(vis));
	for (int i = 2; i * i <= maxn; i++)
		if (!vis[i])
			for (int j = i * i; j <= maxn; j += i)
				vis[j] = 1;
	ans[0] = ans[1] = 0;
	vis[0] = vis[1] = 1;
	for (int i = 2; i <= maxn; i++) {
		ans[i] = ans[i - 1];
		if (!vis[i] && !vis[i - 2])
			ans[i]++;
	}
}
int main() {
	sieve();
	while (cin >> n && n > 0) {
		cout << ans[n] << "n";
	}
	return 0;
}