东方博宜 1176. 素数问题

#include<iostream>
using namespace std;
int main()
{	
	int n ;
	while(cin >> n && n!=0) 
	{
		int count_n ;
		count_n = 0 ;
		int k ;
		for( k = 1 ; k <= n ; k++)
		{
			int count_k ;
			count_k = 0 ;
			int j ;
			for( j = 2 ; j < k ; j++)
			{
				if (k % j != 0) count_k += 1 ;
			}
			if(count_k == k-2)
				count_n += 1 ;
		}
		cout << count_n << endl ;
	}
}