import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        
        int n = Integer.parseInt(sc.next());
        //String s = sc.next();
        
        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);
        }
        
        //System.out.println(max);
    }
}
/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