Difficulty: ★☆☆☆☆
A upper case letter can be eliminated with a correspoding lower case letter.
For instance, a 'Q' can be eliminated with a 'q'.
Your output should be the number(length) of remaining letters.
If the input string is 'bbAABBBaaaC', the remaining letter would be 'BaC'.
Hence the output is 3.
First N（N<=10）represents the number of the testcase.
Follow by N lines strings.
The length should not exceed 100.
Strings contain letters only, which means digits excluded.
The numbers(length) of the remaining string.