import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();


        if (n < 105){
            System.out.println(0);
        } else {
            if (n < 135){
                System.out.println(1);
            } else {
                if (n < 165){
                    System.out.println(2);
                } else {
                    if (n < 189){
                        System.out.println(3);
                    } else {
                        if (n < 195){
                            System.out.println(4);
                        } else {
                            System.out.println(5);
                        }
                    }
                }
            }
        }
    }
}




/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz