Vasya made cards by writing the first N capital letters of the Latin alphabet on them. Vasya put the cards in a pile.
Then he takes the first card from the top and puts it in a new pile. Then he puts the second card at the bottom of this new pile, the third — on top of a new pile, then the fourth — down again, next — up, etc.
After that, it turned out that the cards are strictly alphabetical, if you look at them from top to bottom.
Write a program to print the order in which the cards were in the original pile.
Input
A natural number N is entered (N does not exceed 26).
Imprint
Print the letters written on the cards in the original pile, if viewed from top to bottom (capital latin letters should be printed without spaces between them).
Examples
| # |
Input |
Output |
| 1 |
3 |
BCA |
| 2 |
6 |
CDBEAF |