String change

In this problem you will receive two strings S₁ and S₂ that contain only lowercase letters.
Each time you can swap any two characters of S₁. After swap,both of the two letters will increase their value by one. If the previous letter is 'z',it will become 'a' after being swapped.
That is to say ,"a" becomes "b","b" becomes "c"....."z" becomes "a" and so on.
You can do the change operation in S₁ as many times as you want.
Please tell us whether you can change S₁ to S₂ after some operations or not.

There are several cases.The first line of the input is a single integer T (T <= 41) which is the number of test cases.Then comes the T test cases .

For each case,the first line is S₁,the second line is S₂.S₁ has the same length as S₂ and the length of the string is between 2 and 60.

For each case,output "Case #X: " first, X is the case number starting from 1.If it is possible change S₁ to S₂ output "YES",otherwise output "NO".

3
ab
ba

bac
ddb

aaabb
cbccd

Case #1: NO
Case #2: YES
Case #3: YES

For the first case,it's impossible to change "ab" to "ba" .

For the second case,swap(S1[0],S1[2])->swap(S1[1],S1[2]),meanwhile:bac->dac->ddb.

For the third case,swap(S1[0],S1[3])->swap(S1[1],S1[2])->swap(S1[2],S1[3])->swap(S1[3],S1[4]),
meanwhile:aaabb->caabb->cbbbb->cbccb->cbccd.

miketc@UESTC_Goldfinger

2012 Multi-University Training Contest 6