Question 15
Starting from a positive integer $I$, we first re-arrange its digits and then subtract $1$ from it to get $M$. Now, we again re-arrange the digits of $M$ and add $1$ to it to get $C$. For example, if $I=2358$, we may have $C=2259$, $2358$ and $4284$ among other values. How many different integers $C$ can be obtained if $I=2267$?