Riddle

3 men get a hotel room the room cost $30 they each pay $10. Later the clerk realized he overcharged them and gave the bellhop 5 one dollar bills and told him to split between the 3 guys. Well he couldn't split evenly so he put $2 in his pocket and gave them each $1. That makes the cost of the room $27 and the bellhop had $2 which makes $29 where's the other dollar