package algo;

import java.util.*;

public class sample1 {
	public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	int A = sc.nextInt();
	int B = sc.nextInt();
	List<Integer> list = new ArrayList<>();
	list.add(23);
	list.add(24);
	list.add(25);
	int cnt = 3;
	for(int l : list) {
		for(int i = A; i <= B; i++) {
			if(i == l) {
				cnt--;
			}
		}
	}
	System.out.println(cnt);
	}
}