import java.util.Arrays;
import java.util.Scanner;

public class A000069 {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		String a = s.next();
		String b = s.next();
		s.close();

		char[] ai = a.toCharArray();
		char[] bi = b.toCharArray();
		Arrays.sort(ai);
		Arrays.sort(bi);

		String r = "YES";
		for(int i = 0;i<ai.length;i++) {
			if(ai[i]!=bi[i]) {
				r = "NO";
				break;
			}
		}
		System.out.println(r);
	}

}