Kata

You will be given an Array(a), starting position (i) and number of portion to return (n) . Your task is to return n portion of the array (a) starting from position (i ). The starting position could be negative, in that case you should start counting reverse direction till you get all your n portion. In case you can not find the exact n portion of elements counting from the starting position i or the starting position i is out of the index of the array, you should return -1 (throw an ArgumentOutOfRangeException in C#).

example:

function p([1,2,3,4],1,2)
 should return [2,3]
 
 how ?
 Array => [1,2,3,4]
           | | | |
 index =>  0 1 2 3
 portion     |_|   => [2,3]
 
function p([1,2,3,4],-1,2)
 should return [2,3]
 
 how ?
 Array => [1,  2,  3, 4]
           |   |   |  |
 index=>   -3 -2  -1  0
 portion=>     |___|      =>[2,3]    
 
function p([1],1,5)
 should return -1

how ? 
Array => [1]
          | 
index=>   0
required starting index =>1 , which does not exist so we return -1