A survey of 138 pet owners yielded the following information: 49 pet owners own fish; 53 own a bird; 50 own a cat; 64 own a dog; 2 own all four; 11 own only fish; 16 own only a bird; 10 own fish and a bird; 21 own fish and a cat; 24 own a bird and a dog; 29 own a cat and a dog; 3 own fish, a bird, a cat, and no dog; 1 owns fish, a bird, a dog, and no cat; 9 own fish, a cat, a dog, and no bird; and 10 own a bird, a cat, a dog, and no fish. How many of the surveyed pet owners have no fish, no birds, no cats, and no dogs? (They own other types of pets.)