Mr. Smith goes to the doctor's office to collect his wife's test results. The insurance clerk says to him, "I'm sorry, sir, but there has been a bit of a mix-up and we have a problem. When we sent the samples from your wife to the lab, the samples from another Mrs. Smith were sent at the same time and we are now uncertain which one is your wife's. Frankly, the situation is either bad or terrible! "What do you mean?" "Well, one Mrs. Smith tested positive for Alzheimer's and the other Mrs. Smith has tested positive for AIDS. We can't tell which is your wife." "That's terrible! Can we do the test over?" "Normally, yes. But you have an HMO and they won't pay for these expensive tests more than once in a year, so we can't repeat the test until next year." "Well, what am I supposed to do now?" "The HMO recommends that you drop your wife off on the outskirts of town........ If she remembers the way home, don't sleep with her."