HMMT November 2011 U24

Three not necessarily distinct positive integers between 1 and 99, inclusive, are written in a row on a blackboard. Then, the numbers, without including any leading zeros, are concatenated to form a new integer $N$. For example, if the integers written, in order, are 25, 6, and 12, then $N=25612$ (and not $N=250612$ ). Determine the number of possible values of $N$.