A person wanted to get into a members only disco but because she couldn't become a member, the person hid and watched as the guard at the door of the disco house said a number to each members as they approached, the member would respond with a number of their own, if the member responded with the correct number theirs were let in, if they responded incorrectly they were thrown out. One members come up to the guard, the man said twelve and the member responded with six and was let in. Another member came to the door, the man said six and the member responded with three and was let in. Believing she had heard enough, the reject went up to the man, the man said ten, and the reject said five, but was not let in, what should the rejected person have said?