OK Parity

You are given a string s of length n consisting only of two characters O and K Let O(s) be the number of occurrences of string “OK” in s as a substring. Thus, K(s) is the number of occurrences of “KO” in s as a substring. In one step, you can choose any index i and replace s[i] with character 'O' or 'K'. What is the minimum number of steps you need to make to achieve O(s)=K(s)? Some Explanatio