a=input()
b=input()
def check(a,b):
if a==b:
return True
length=len(a)
if length!=len(b) or length%2!=0:
return False
a1=a[0:length//2]
a2=a[length//2:length]
b1=b[0:length//2]
b2=b[length//2:length]
if check(a1,b1) and check(a2,b2):
return True
if check(a1,b2) and check(a2,b1):
return True
return False
res=check(a,b)
if res:
print('YES')
else:
print('NO')