Longest special subsequencesYou are given a string S of the length n consisting of only lowercase English alphabets.If the two consecutive characters in a subsequence have a difference that is no more than k$,$ then it is called a special subsequence. Find the length of the longest special subsequence.Input formatFirst line: t $($number of test cases$)$Next t line: Three space$-$separated integers n$,$ k$,$ and SOutput formatFor each test case, print the length of the longest special subsequence in a new line.Constraints$1<=$ t $<=101<=$ n $<=10^51<=$ k $<=26$Sample input$172$ afcbedgSample output$4$ExplanationOne of the longest special sequence present in "afcbedf" is a$,$ c$,$ b$,$ d$.$ It is special because lacl $<=2,$ Ic$-$bl $2$ and $1$ b$-$dl $<=2$Note:Your code must be able to print the sample output from the provided sample input. However, your code is run against multiple hidden test cases. Therefore, your code must pass these hidden test cases to solve the problem statement.LimitsTime Limit: $1\mathrm{.}0$ sec$($s$)$ for each input fileMemory Limit $256$ MBSource Limit $1024$ KBScoringScore is assigned if any testcase passesAllowed LanguagesPython, Python $3$