AT_abc456_c [ABC456C] Not Adjacent

You are given a string $ S $ consisting of `a`, `b`, `c`. Find the number of non-empty **substrings** of $ S $ in which no two adjacent characters are the same, modulo $ 998244353 $ . Two substrings are considered distinct if they are taken from different positions, even if they are identical as strings. What is a substring? A **substring** of $ S $ is a string obtained by deleting zero or more characters from the beginning and zero or more characters from the end of $ S $ . For example, `ab` is a substring of `abc`, but `ac` is not a substring of `abc`.

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

Output the answer.

### Sample Explanation 1 The substrings in which no two adjacent characters are the same are the following six: - `a` (from the $ 1 $ st to the $ 1 $ st character of $ S $ ) - `b` (from the $ 2 $ nd to the $ 2 $ nd character of $ S $ ) - `b` (from the $ 3 $ rd to the $ 3 $ rd character of $ S $ ) - `c` (from the $ 4 $ th to the $ 4 $ th character of $ S $ ) - `ab` (from the $ 1 $ st to the $ 2 $ nd character of $ S $ ) - `bc` (from the $ 3 $ rd to the $ 4 $ th character of $ S $ ) Note that, as with the $ 2 $ nd and $ 3 $ rd entries, two substrings are considered distinct if they are taken from different positions, even if they are identical as strings. ### Constraints - $ S $ is a string of length between $ 1 $ and $ 3 \times 10^5 $ , inclusive, consisting of `a`, `b`, `c`.