import java.util.*;

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

        int start = in.nextInt();
        int end = in.nextInt();
        int count = 3;
        
        for(int i=start; i<=end; i++){
            if(i==23 || i==24 || i==25){
                count--;
            }
        }
        System.out.println(count);
        
    }
}