        exist_value = current.value
        next_value = current.next.value
        print(next_value)
        print(exist_value)
        if exist_value == next_value:
            current.next = current.next.next
        if current.next is None:
            break
        if current.value != current.next.value:
            print('possible error')
            current = current.next
    return dummy.next

    