Given a string of uppercase or lowercase characters, print how many letters of the alphabet are not contained in the string.

A letter is considered to not be contained in the string if there are no occurrences of it in the string, either uppercase or lowercase.

Input Specification

One line, containing a string of uppercase or lowercase characters. The length of this string is guaranteed to be less than or equal to ~1000~ characters.

Output Specification

One integer, the number of letters of the alphabet that are not contained in the string.

Sample Input 1

abcdefghijklmnopqrstuvwxy

Sample Output 1

1

Sample Explanation

All letters occur in the string except for z.

Sample Input 2

AcDefghijxmNpqRstuvWYzzkL

Sample Output 2

2

Sample Explanation

The letters that are missing are b and o. Note that characters that occur more than once do not affect the number of letters that are not contained in the string.