from collections import defaultdict
A = raw_input()
B = raw_input()
dictA, dictB = defaultdict(int),defaultdict(int) 
for c in A:
	dictA[c] += 1
for c in B:
	dictB[c] += 1

for c in A:
	if (dictA[c] != dictB[c]):
		print "NO"
		exit(0)

print "YES"