import java.util.Scanner;
public class Main
{
	public static void main(String[] Args)
	{
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int n;
		if(a%30 == 0)
			n = a/30;
		else
			n = a/30+1;
		System.out.println(n);

	}
}
/**************************************************************
	Problem: 1632
	User: admin
	Language: Java
	Result: Accepted
	Time:682 ms
	Memory:40240 kb
****************************************************************/