fn main() -> Result<(), std::io::Error> {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    let input_num: Vec<i32> = s.trim()
        .split_whitespace()
        .map(|e| e.parse::<i32>().unwrap())
        .collect();

    let a = input_num[0];
    let b = input_num[1];

    let lo = 23;
    let up = 25;

    let cnt = (a..=b).fold(0, |sum, item| sum + (item <= up && item >= lo) as i32);
    println!("{}", 3 - cnt);

    Ok(())
}