Problem E
Howl
Returning to the Beautiful Gloomy Outback (BGO) after a strenuous trip to the city, you hear a faint howl in the distance. Instantly you realize it is your friend Fenrir inviting you to a howling contest.
In order to make an impressive howl that wins the contest, you know that your howl must fulfill the following criteria in order to be valid:
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It must consist of a combination of the letters A, H, O and W. Each letter must occur at least once.
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The howl can not contain two consecutive W’s, or two consecutive H’s.
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The howl can not contain an H followed immediately by a W or an A.
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There can never be an A after the first occurrence of an O.
Can you produce a longer howl than Fenrir and win the contest?
Input
The first and only line of input contains a single word, the howl of Fenrir. Since Fenrir is a proper wolf, his howls are always valid. Writing down Fenrir’s howl will require at most $1$ MB of computer memory.
Output
A valid howl which will win the howling contest.
| Sample Input 1 | Sample Output 1 |
|---|---|
AAHOOW |
AWAWHOO |
