ABCD - Colours A, B, C, D

Consider a table with 2 rows and 2N columns (a total of 4N cells). Each cell of the first row is coloured by one of the colours A, B, C, D such that there are no two adjacent cells of the same colour. You have to colour the second row using colours A, B, C, D such that:

  • There are exactly N cells of each colour (A, B, C and D) in the table.
  • There are no two adjacent cells of the same colour. (Adjacent cells share a vertical or a horizontal side.)

It is guaranteed that the solution, not necessarily unique, will always exist.

Input

[a natural number N ≤ 50000]

[a string of 2N letters from the set {A, B, C, D}, representing the first row of the table]

Output

[a string of 2N letters from the set {A, B, C, D}, representing the second row of the table]

Example

Input:
1
CB

Output:
AD
Input:
2
ABAD

Output:
BCDC

Added by:Adrian Satja Kurdija
Date:2011-03-13
Time limit:0.300s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM64 GOSU
Resource:inspired by a math puzzle

hide comments
2013-01-30 02:36:14 Khoi Tran
Can anyone take a look at my solution? Why does it exceed time limit?
It's O(n) and I tried my best to optimize everything. Is it just a Python limitation?
2013-01-14 21:12:50 ginnipkj
Sometimes u need to be greedy....:)
2013-01-11 11:48:09 Shubham Somani
simple DFS! :P
2013-01-09 06:21:22 Akhil Rao
for testcase
3
DBADBA
I am getting
CACBCD
Is it right??
2013-01-03 21:34:03 Dhruv Goel
There was no extra line needed between n and input string for AC (in my case).
2012-12-21 19:25:33 Anuj_LuckFove!
nice ques :) finally AC..no need to think too much for this..simplistic approach will work..
2012-12-18 03:21:54 triveni
Thanks beginner, '\n' caused me also many wrong answers.. finally AC.. :(
2012-12-12 05:31:52 Paul Draper
@Romal Thoppilan, some might think "TRickY but straightforward !" doesn't make much sense.
2012-12-11 19:25:41 Retaliation
I am getting wrong ans on 18th test case. aren't every possible solutions covered for that test case ?
2012-09-14 12:55:02 abdelkarim
i spend month to solve it and got AC
after 19 WA
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