#[macro_export]
macro_rules! setup {
    { mut $input:ident: SplitWhitespace $(,)? } => {
        use std::io::Read;
        let mut buf = String::new();
        std::io::stdin().read_to_string(&mut buf).unwrap();
        let mut $input = buf.split_whitespace();
    };
}

#[macro_export]
macro_rules! parse_next {
    ($str_iter:expr) => {
        $str_iter.next().unwrap().parse().unwrap()
    };
}

fn main() {
    setup! { mut input: SplitWhitespace };

    let n: usize = parse_next!(input);
    let mut a: Vec<i64> = (0..n).map(|_| parse_next!(input)).collect();

    a.sort();

    let ans = match a.len() % 2 {
        0 => {
            let x = a[(a.len() / 2) - 1];
            let y = a[(a.len() / 2) + 1 - 1];
            ((x as f64) + (y as f64)) / 2.0
        }
        1 => a[((a.len() + 1) / 2) - 1] as f64,
        _ => unreachable!(),
    };

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