#coding: UTF-8

import sys
from math import pi
from collections import deque
from functools import reduce

### defs ###

### main ###
A = sys.stdin.readline().strip('\r\n')
B = sys.stdin.readline().strip('\r\n')
a = [c for c in A]
b = [c for c in B]
a.sort() 
b.sort()
ans = {True:'YES',False:'NO'}
print(ans[a==b])