A string of lowercase letters is called alphabetical if deleting zero or more of its letters can result in the alphabet string
Given a string , determine the minimum number of letters to insert anywhere in the string to make it alphabetical.
The input consists of a single line containing the string .
It is guaranteed that consists of lowercase ASCII letters
Print, on a single line, a single integer indicating the minimum number of letters that must be inserted in order to make the string alphabetical.
Sample Input 1
Sample Output 1
Sample Input 2
Sample Output 2