spoj#ABCD. Colours A, B, C, D
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</p>Output: AD
Input: 2 ABAD Output: BCDC