import java.util.Scanner;

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