import java.util.*;


public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        int ans = 3;
        for (int i = a; i <= b; i++) {
            switch (i) {
                case 23:
                    ans--;
                    break;
                case 24:
                    ans--;
                    break;
                case 25:
                    ans--;
                    break;
                default:
                    break;
            }
        }
        System.out.println(ans);
    }
}