import java.util.*;
import java.lang.*;

public class N597{
  public static void main(String[] args) {

    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    String str[] = new String[N];


    for(int i = 0; i < N; i++){
      str[i] = sc.next();
    }
    for(int i = 0; i < N; i++){
      System.out.print(str[i]);
    }
    System.out.println("");
  }
}