#include <stdio.h>
#define N 5

int a[N] = {105, 135, 165, 189, 195}, c = 0;

int main()
{		
	int n, i;
	
	scanf("%d", &n);
	for(i = 0; i < N; i++){
		if(a[i] <= n) c++;
	}
	printf("%d\n", c);
			
	return 0;
}