package algo;

import java.util.*;

public class sample7 {

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