Acar dealer has many vehicles on his lot. 8 of the vehicles are vans, 12 of the vehicles are red, and 38 vehicles have automatic transmissions. 7 of the vehicles are vans with automatic transmissions, 3 of the vehicles are red vans, and 10 of the vehicles are red with automatic transmissions. if there are 3 vehicles that are automatic red vans and 4 vehicles that are neither vans nor red nor automatic, how many total vehicles does the dealer have on his lot?