DMOPC '18 Contest 5 P4 - An Art Gallery Problem
View as PDFBob is admiring a beautiful postmodern exhibit at the local art gallery. The exhibit consists of  colourful neon lamps in a line, labelled 
 to 
, and each lamp can be one of two colours: a vibrant fuchsia or a soothing aquamarine.
The exhibit also happens to be interactive. There are  buttons that the visitors can press, labelled 
 to 
. Pressing button 
 will simultaneously change the colours of lamps 
 and 
 (from fuchsia to aquamarine or aquamarine to fuchsia), but only if those lamps are the same colour. Obviously, this represents the profound fragility and changeable nature of the human condition.
Bob notices that the colours of the lamps currently form pattern . He thinks they would look good in pattern 
, so he wants to know if it is possible to get to 
 from 
 by a sequence of zero or more button presses.
Constraints
Subtask 1 [20%]
Subtask 2 [20%]
Subtask 3 [60%]
Input Specification
The first line will contain one integer, .
The second line will contain a string of  characters, either 
F (fuchsia) or A (aquamarine), pattern .
The third and final line will contain a string of  characters, either 
F or A, pattern .
Output Specification
Output YES if it is possible to get to  from 
 and 
NO otherwise.
Sample Input 1
6
FAAFFF
FFAAFF
Sample Output 1
YES
Sample Input 2
6
FAFAFA
AFAFAF
Sample Output 2
NO
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