use std::io;

fn main() {
    let mut n = String::new();
    io::stdin().read_line(&mut n).unwrap();
    let n: usize = n.trim().parse().unwrap();

    let mut a = String::new();
    io::stdin().read_line(&mut a).unwrap();
    let mut a: Vec<i32> = a.trim()
        .split(' ')
        .take(n)
        .map(|s| s.parse().unwrap())
        .collect();
    a.sort();

    let median = match n % 2 {
        0 => (a[n / 2 - 1] + a[n / 2]) as f32 / 2.0,
        _ => a[n / 2] as f32,
    };

    println!("{}", median);
}