A perfect string is a string in which the absolute difference between adjacent characters is equal to **2, 3 or 4**. For example, if the position of the characters \'d\' and \'g\' is 4 and 7 respectively, then the absolute difference between their positions is 3. Convert a simple string into a perfect string by using the **minimum amount of time**. The time to change one character to another takes the same amount of time that is equal to the absolute difference between the characters.\n \nYou need to convert string S into a perfect string by using the minimum amount of time.\nNote: The string contains all lowercase characters\n\nInput: \nString S\n\nOutput:\nPrint the minimum changes that are required to modify the string S into a perfect string\n \nSample Input\nabcdef\n\nSample Output\n5\n \nExplanation\nOne string with minimum cost is "acaceg" . The cost to convert abcdef to "acaceg" is 5

A perfect string is a string in which the absolute difference between adjacent characters is equal to 2, 3 or 4. For example, if the position of the characters 