Field of Wonders#7340

Field of Wonders

1 second

64 megabytes

Very easy

Petryk and Marichka enjoy playing the game "Field of Wonders." In this game, Marichka writes down a word using uppercase English letters, and Petryk attempts to guess it. Each time Petryk guesses a letter correctly, it is revealed in all positions where it appears in the word. What is the minimum number of guesses Petryk needs to identify the entire word?

Input

A word composed of uppercase English letters ( $\leq 100$ characters).

Output

The minimum number of guesses required to reveal the entire word.

Examples

Example 1

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