import java.util.*;

public class Main {
    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.toString());
    }
}