#P2672. Hotkeys
Hotkeys
Description
Tom is designing a menu system for a test editor. The menu consists of some menuitems, and each menuitem may contain some sub-menuitems (a sub-menuitem is also a menuitem) recursively, e.g., menuitem "File" may contain sub-menuitems "Open", "Save", "Save As", "Recent Files", "Send" and "Exit", and "Recent Files" may contain "Setting File", "Send" may contain "Mail" and "Fax". A menuitem may contain several words, and it is confirmed that the first letter in each word is a capital letter, and that the other letters are all small letters.
Each menuitem is associated with a hotkey, the menu is easier to use if the hotkeys are easier to remember. So Tom wants that the hotkey can only be a capital letter in a menuitem, which means the first letter in each word. Take "Save As" for example, the hotkey can only be 'S' or 'A'. It is clear that sub-menuitems of a menuitem can't be associated with the same hotkey, e.g., "Save" and "Save As" can't both use hotkey 'S', because they are both sub-menuitems of menu "File".
Since Tom believes press the same key twice is not convenient, he requests that the hotkeys of a menuitem and its sub-menuitems can't duplicate. In the previous example, "File" and "Recent Files" can't use the same hotkey 'F'. But this rule just affects the menuitem and its direct sub-menuitem, so "File" and "Setting File" can use the same hotkey 'F'.
Given a menu description, Tom wants to know whether it is possible to assign a hotkey for each menuitem or not.
Input
The menu is described as follows: a menuitem occupies a single line, and the sub-menuitems of a menuitem is listed just below this menu item. The description of the sub-menuitems starts with a "<" before the first sub-menuitem and ends with a ">" after the last sub-menuitem. "<" and ">" will take a whole line by itself. Since we may consider the menuitems in the top level belong to a global menu, there is always a "<" at the beginning of the input and a ">" at the end of the input.
Each menuitem may contain words and white spaces separating them. The length of a menuitem name is less than 50 characters.
There are no more than 10000 menuitems. It is confirmed that all the input are legal menuitems described above.
Output
A single line contains "Got It!" if a hotkey can be assigned to each menuitem; otherwise, output "No Solution".
<
File
<
Open
Save
Save As
Recent Files
Send
<
Mail
Fax
>
Exit
>
Edit
<
Find
Replace
Replace All
>
>
No Solution
Source
Beijing 2005 Preliminary