import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		StringBuilder sb = new StringBuilder();
		for(int i = 0; i < N; i++) {
			sb.append(scan.next());
		}
		scan.close();
		System.out.println(sb);
	}
}