import java.util.Scanner;

class no597{
	public static void main(String[] args) {
		Scanner stdIn=new Scanner(System.in);
		short n=stdIn.nextShort();
		String[] s=new String[n];
		for(short i=0;i<n;i++) s[i]=stdIn.next();
		for(short i=0;i<n;i++) System.out.print(s[i]);
		System.out.println();
	}
}