def rotate(arr,index)
  rotated_array = []
  arr.each_with_index do |a,i|
    new_index = i + index
    if new_index >= arr.length
      while new_index >= arr.length do
        new_index = new_index - arr.length
      end
      rotated_array.insert(new_index, a)
    else
      rotated_array.insert(new_index, a)
    end
  end
 rotated_array.compact
end