package main

import "fmt"

func sort(s []byte) []byte {
	for i := 0; i < len(s); i++ {
		for j := 1; j < len(s)-i; j++ {
			if s[j-1] > s[j] {
				s[j-1], s[j] = s[j], s[j-1]
			}
		}
	}
	return s
}

func main() {
	s := make([]byte, 10)
	t := make([]byte, 10)
	fmt.Scan(&s)
	fmt.Scan(&t)
	if string(sort(s)) == string(sort(t)) {
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}