Missing Dollar Riddle

Three men stroll into a restaurant and share a $30 meal. After paying for the meal, the owner of the restaurant realizes the waiter overcharged the men, and orders the waiter to return $5 back to the men. Not knowing how to divide the money the waiter decides to keep $2 and give each of the men $1 back. So each man ended up paying $9 ($10-$1), the waiter kept $2. So thats $9+$9+$9+$2 = $29. Where did the last dollar end up?