fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let h: isize = itr.next().unwrap().parse().unwrap();
    let a: isize = itr.next().unwrap().parse().unwrap();
    let d: isize = itr.next().unwrap().parse().unwrap();

    let mut ans = 0;
    if d as f64 / a as f64 >= 1.5 {
        ans += h / d;
        if h - ans * d > a {
            println!("{}", ans as f64 * 1.5 + 1.5);
            return;
        } else if a - ans * d == 0 {
            println!("{}", ans as f64 * 1.5);
            return;
        } else {
            println!("{}", ans as f64 * 1.5 + 1.0);
            return;
        }
    } else {
        ans += h / a;
        if h - ans * d > a {
            println!("{}", ans as f64 + 1.5);
            return;
        } else if a - ans * d == 0 {
            println!("{}", ans);
            return;
        } else {
            println!("{}", ans + 1);
            return;
        }
    }
}