AT_abc404_a [ABC404A] Not Found

You are given a string $ S $ of length between $ 1 $ and $ 25 $ consisting of lowercase English letters. Output one lowercase English letter that does not appear in $ S $ . If there are multiple such letters, you may output any one of them.

The input is given from Standard Input in the following format: > $ S $

Output one lowercase English letter that does not appear in $ S $ . If there are multiple such letters, you may output any one of them.

### Sample Explanation 1 $ S= $ `a`. Any lowercase English letter other than `a` (that is, `b`, `c`, …, or `z`) is a correct answer. ### Sample Explanation 2 The lowercase English letters not included in $ S $ are `e` and `g`. ### Constraints - $ S $ is a string of length between $ 1 $ and $ 25 $ (inclusive) consisting of lowercase English letters.