Timmy can usually make six paper airplanes in an hour. However, if he gets interrupted by his parents, he can only make four per hour.

His friend John can make seven paper airplanes per hour.

One day, Timmy and John decide to have a three-hour long

contest to see who can make the most paper airplanes. During the

contest, Timmy is interrupted once every hour. John also had to

take a break and do chores for an hour. How many more paper

airplanes does the winner make?