you give string s integer k you choose character string change uppercase english character you perform operation k timesreturn length long substre contain letter perform operation Example 1input s ABAB k 2output 4explanation Replace as Bs vice versaexample 2input s AABABBA k 1output 4explanation replace a middle b form AABBBBAThe substre BBBB long repeat letter 4 Constraints1 slength 105s consist uppercase English letters0 k slength