fn main() {
    let n: Vec<u64> = input_line();
    let mut days = 3;

    for i in 23..=25 {
        if n[0] <= i && i <= n[1] {
            days -= 1;
        }
    }

    println!("{}", days);
}

#[allow(unused)]
fn input_line<T: std::str::FromStr>() -> Vec<T> {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}