use proconio::input;
fn main() {
    input! {
        l: usize,
        r: usize,
    }
    let mut a: Vec<usize> = (l..=r).collect();
    a.push(0);
    let mut cnt = 0;
    for i in 0..a.len() {
        if a[i] == 295 && a[i+1] == 296 { cnt += 1; }
        if a[i] == 416 && a[i+1] == 417 { cnt += 1; }
    }
    println!("{cnt}");
}