A survey of 1,095 tourists visiting Orlando was taken. Of those surveyed: 295 tourists had visited the Magic Kingdom
290 tourists had visited LEGOLAND
280 tourists had visited Universal Studios
66 tourists had visited both the Magic Kingdom and LEGOLAND
68 tourists had visited both the Magic Kingdom and Universal Studios
51 tourists had visited both LEGOLAND and Universal Studios
18 tourists had visited all three theme parks
How many tourists had not visited any of these three theme parks?