use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {
        r: [u8],
    }

    println!("{}", output(solve(r)))
}

fn solve(r: Vec<u8>) -> Vec<f32> {
    r.into_iter()
        .map(|r| 1.299038105676657 * (r as u16).pow(2) as f32)
        .collect()
}

fn output(ans: Vec<f32>) -> String {
    ans.into_iter()
        .map(|x| x.to_string())
        .collect::<Vec<_>>()
        .join("\n")
}