codeforces#P1914A. Problemsolving Log
Problemsolving Log
Description
Monocarp is participating in a programming contest, which features problems, named from 'A' to 'Z'. The problems are sorted by difficulty. Moreover, it's known that Monocarp can solve problem 'A' in minute, problem 'B' in minutes, ..., problem 'Z' in minutes.
After the contest, you discovered his contest log — a string, consisting of uppercase Latin letters, such that the -th letter tells which problem Monocarp was solving during the -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.
The first line contains a single integer () — the number of testcases.
The first line of each testcase contains a single integer () — the duration of the contest, in minutes.
The second line contains a string of length exactly , consisting only of uppercase Latin letters, — Monocarp's contest log.
For each testcase, print a single integer — the number of problems Monocarp solved during the contest.
Input
The first line contains a single integer () — the number of testcases.
The first line of each testcase contains a single integer () — the duration of the contest, in minutes.
The second line contains a string of length exactly , consisting only of uppercase Latin letters, — Monocarp's contest log.
Output
For each testcase, print a single integer — the number of problems Monocarp solved during the contest.