At my office there is often confusion created around our five-digit contract numbers. A common error involved numbers with repeated consecutive digits, for example 54467 might be wrongly written as 54667. To combat this problem it was decided that, for the contract numbers beginning with 6, no repeated consecutive digits would be allowed. So 60000 is out straight away. In fact the first acceptable number of this new scheme would be 60101.
How many of the 10000 possible numbers from 60000 to 69999 can still be used as contract numbers?