AT_abc397_b [ABC397B] Ticket Gate Log

> Takahashi aggregated usage records from ticket gates. However, he accidentally erased some records of entering and exiting stations. He is trying to restore the erased records. You are given a string $ S $ consisting of `i` and `o`. We want to insert zero or more characters at arbitrary positions in $ S $ so that the resulting string satisfies the following conditions: - Its length is even, and every odd-numbered (1st, 3rd, ...) character is `i` while every even-numbered (2nd, 4th, ...) character is `o`. Find the minimum number of characters that need to be inserted. It can be proved under the constraints of this problem that by inserting an appropriate finite number of characters, $ S $ can be made to satisfy the conditions.

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

Print the answer.

### Sample Explanation 1 We can insert `o` after the 3rd character to form `ioio` to satisfy the conditions. The conditions cannot be satisfied by inserting zero or fewer characters. ### Sample Explanation 2 We can insert `o` after the 1st character and `i` after the 3rd character to satisfy the conditions. The conditions cannot be satisfied by inserting one or fewer characters. ### Sample Explanation 3 $ S $ already satisfies the conditions. ### Constraints - $ S $ is a string of length between $ 1 $ and $ 100 $ , consisting of `i` and `o`.