import java.util.Scanner;

public class Main {

    static int number_0 = 0 , number_1 = 0;

    public static void main(String[] args) {
        input();
        if (number_0 > number_1){
            while (number_0 > 0){
                System.out.print("0");
                number_0--;
            }
        }
        else {
            while (number_1 > 0){
                System.out.print("1");
                number_1--;
            }
        }
    }


    public static void input(){
        Scanner in = new Scanner(System.in);
        String s = in.nextLine();
        s = in.nextLine();
        for (int i = 0; i < s.length(); i++){
                if (s.charAt(i) == '0') 
                   number_0++;
                else if (s.charAt(i) == '1')     
                   number_1++;
        }
    }
}