fn main() {
    let stdin = std::io::read_to_string(std::io::stdin()).unwrap();
    let mut stdin = stdin.split_ascii_whitespace();

    let n: usize = stdin.next().unwrap().parse().unwrap();
    let s: Vec<String> = (0..n)
        .map(|_| stdin.next().unwrap().parse().unwrap())
        .collect();

    println!("{}", output(solve(s)));
}

fn solve(s: Vec<String>) -> String {
    s.join("")
}

fn output(ans: String) -> String {
    ans
}