use proconio::input;

fn get_current(n: usize) -> String {
    if n <= 295 {
        "C++".to_string()
    } else if n <= 416 {
        "Rust".to_string()
    } else {
        "Python".to_string()
    }
}

fn main() {
    input!{
        l: usize,
        r: usize
    }
    let mut ans = 0;
    let mut prev = get_current(l);
    for i in l+1..=r {
        let current = get_current(i);
        if current != prev {
            ans += 1;
            prev = current;
        }
    }
    println!("{}", ans);
}