import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		String b = sc.next();
		int n1 = a.length();
		int n2 = b.length();
		if(n1 != n2) {
			System.out.println("NO");
			return;
		}
		Map<String, Integer> map1 = new HashMap<>();
		Map<String, Integer> map2 = new HashMap<>();
		for(char c = 'a' ; c <= 'z' ; c++) {
			map1.put("" + c, 0);
			map2.put("" + c, 0);
		}
		for(int i = 0 ; i < n1 ; i++) {
			map1.put("" + a.charAt(i), map1.get("" + a.charAt(i)) + 1);
			map2.put("" + b.charAt(i), map2.get("" + b.charAt(i)) + 1);
		}
		int cnt = 0;
		for(int i = 0 ; i < n1 ; i++) {
			if(map1.get("" + a.charAt(i)) == map2.get("" + a.charAt(i))) {
				cnt++;
			}
		}
		if(cnt == n1) {
			System.out.println("YES");
		} else {
			System.out.println("NO");
		}
 	}
}