import java.util.*;

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