def neg_pos(arr, index) # return the element of the array at the position index from the end of the list arr[-index] end

def first_element(arr) # return the first element of the array arr.first end

def last_element(arr) # return the last element of the array arr.last end

def first_n(arr, n) arr.take(n) # return the first n elements of the array end

def drop_n(arr, n) arr.drop(n) # drop the first n elements of the array and return the rest end

evrey thing is given in the syntax all you need is to just observe it