from collections import Counter

A = input()
B = input()
A_list = []
B_list = []

for c1, c2 in zip(A, B):
    A_list.append(c1)
    B_list.append(c2)

A = sorted(A_list)
B = sorted(B_list)

yes_flag = True
for c1, c2 in zip(A, B):
    if c1 != c2:
        print('NO')
        yes_flag = False
        break

if yes_flag:
    print('YES')