const INF: f64 = 1e18;

fn main() {
    let mut had = String::new();
    std::io::stdin().read_line(&mut had).ok();
    let had: Vec<usize> = had.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let h = had[0];
    let a = had[1];
    let b = had[2];

    let mut dp = vec![INF; h+1];
    dp[0] = 0.;
    for i in 0..h {
        dp[(i+a).min(h)] = dp[(i+a).min(h)].min(dp[i] + 1.);
        dp[(i+b).min(h)] = dp[(i+b).min(h)].min(dp[i] + 1.5);
    }
    println!("{}", dp[h]);
}