fn main() {
    let mut input = String::new();
    std::io::stdin().read_line(&mut input).unwrap();

    input = String::new();
    std::io::stdin().read_line(&mut input).unwrap();

    let nums = input.trim().split_whitespace();

    let mut v: Vec<i32> = Vec::new();
    for i in nums {
        v.push(i.parse::<i32>().unwrap());
    }
    v.sort_by(|a, b| a.cmp(b));

    let length = v.len();
    let median: f32;
    
    if length % 2 == 0 {
        median = (v[(length / 2) - 1] as f32 + v[length / 2] as f32) / 2.0;
    }
    else {
        median = v[length / 2] as f32;
    }
    
    println!("{}", median);
}