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

    def __getitem__(self, index):
        head = self
        while index > 0:
            if head.next is not None:
                head = head.next
                index -= 1
            else:
                raise IndexError
        return head.data

    def set(self, new_item, index):
        head = self
        while index > 0:
            if head.next != None:
                head = head.next
                index -= 1
            else:
                raise IndexError
        head.data = new_item
        return head.data

    def insert(self, new_item, index):
        head = self
        while index > 0:
            if head.next != None:
                head = head.next
                index -= 1
            else:
                return None
        head.next = Node(new_item, head.next)


if __name__ == '__main__':
    n = Node(2, Node(8, Node(10)))
    n.insert(7, 2)
    while n != None:
        print(n.data)
        n = n.next