A. Problemsolving Logtime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputMonocarp is participating in a programming contest, which features 26 problems, named from 'A' to 'Z'. The problems are sorted by difficulty. Moreover, it's known that Monocarp can solve problem 'A' in 1 minute, problem 'B' in 2 minutes, ..., problem 'Z' in 26 minutes.After the contest, you discovered his contest log — a string, consisting of uppercase Latin letters, such that the i-th letter tells which problem Monocarp was solving during the i-th minute of the contest. If Monocarp had spent enough time in total on a problem to solve it, he solved it. Note that Monocarp could have been thinking about a problem after solving it.Given Monocarp's contest log, calculate the number of problems he solved during the contest.InputThe first line contains a single integer t (1 \le t \le 100) — the number of testcases.The first line of each testcase contains a single integer n (1 \le n \le 500) — the duration of the contest, in minutes.The second line contains a string of length exactly n, consisting only of uppercase Latin letters, — Monocarp's contest log.OutputFor each testcase, print a single integer — the number of problems Monocarp solved during the contest.ExampleInput
36ACBCBC7AAAAFPC22FEADBBDFFEDFFFDHHHADCCOutput
3
1
4

36ACBCBC7AAAAFPC22FEADBBDFFEDFFFDHHHADCC
3 1 4 
['implementation', 'strings', '*800']