use std::io::*;
use std::str::*;

fn read<T: FromStr>(sl: &mut StdinLock) -> Option<T> {
    let s = sl.by_ref().bytes().map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>();

    s.parse::<T>().ok()
}

fn run(sl: &mut StdinLock) {
    let n = read::<i32>(sl).unwrap();
    let mut xs = (0..n).map(|_| read::<i32>(sl).unwrap()).collect::<Vec<_>>();
    xs.sort();

    let i = (n / 2) as usize;
    if n % 2 == 0 {
        println!("{}", (xs[i - 1] + xs[i]) as f32 / 2.0f32);
    }
    else {
        println!("{}", xs[i]);
    }
}

fn main() {
    let s = stdin();
    let mut sl = s.lock();
    run(&mut sl);
}