def head(l) :
    return l[0]

    
def tail(l) :
    return l[1:]

class Node :
    def __init__ (self, cargo = None, next = None) :
        self.cargo = cargo
        self.next = next

    def __str__ (self) :
        return str(self.cargo)
    
def print_ll(linked_list) :
    print(linked_list)
    if linked_list.next <> None :
        print_ll(linked_list.next)
        
node1 = Node("test")
node2 = Node(3)
node2.next = node1
node3 = Node([1,2,3], node2)
node0 = Node("at the back")
node1.next = node0

def nth_element(linked_list, num) :
    if num==0 :
        return linked_list
    else :
        return nth_element(linked_list.next, num-1)