use proconio::input;

fn main() {
    input! {
        l: usize, r: usize,
    }

    let f = |i: usize| {
        if i < 296 {
            0
        } else if i < 417 {
            1
        } else {
            2
        }
    };
    let ans = (l..r).filter(|&i| f(i) != f(i + 1)).count();
    println!("{ans}");
}