2010年Puzzleup数学竞赛−第15题: Number Pairs

castelu

                                                                                      Number Pairs

    We have a number that is written by using numerals exactly twice.  The number of digits between each pair is different.

    What is the possible maximum value for this number?

    Example: 988797 is such a number (There are 3 digits between two 9's,zero digits between two 8's, and one digit between two 7's).