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Obviously our number can't be , so the maximum possible number of digits is .
If our number is a number, then there are possibilities: to .
If our number is a number, there are possibilities for the tens digit (anything but and ) and possibilities for the units digit for a total of numbers.
If our number is a number, there are possibilities for the hundreds digit and possibilities for the tens and for the units digits for a total of .
So, the total is .