fn main() {
    let mut line = String::new();
    let _ = std::io::stdin().read_line(&mut line);
    let num: i32 = line.trim().parse().unwrap();

    let mut line = String::new();
    let _ = std::io::stdin().read_line(&mut line);
    let mut numbers: Vec<i32> = line.trim().split_whitespace().map(|n| n.parse().unwrap()).collect();
    numbers.sort();

    let mid = num as usize / 2;
    if num % 2 == 0 {
        println!("{}", (numbers[mid-1] as f64 + numbers[mid] as f64) / 2.0);
    } else {
        println!("{}", numbers[mid]);
    }
}