There are three machines named "truth," "error," and "random" (but you don't know who they are). Among them, "truth" always tells the truth, "error" always tells lies, and "random" ignores the question's content and answers randomly. Every time you can ask a question to one of the machines, the question can only be yes or no. This machine will respond with DA and JA. One of these two words means "yes," while the other means "no," but you don't know which one. Your task is to use three questioning opportunities to determine the identities of the three machines A, B, and C.
It should be noted that you can ask the same machine multiple times; therefore, these three questions are not necessarily addressed to these three machines in that order. Furthermore, it does not have to decide who to ask and what questions to ask each time. According to the previous answers, the content and object of the subsequent questions can be "flexible." "Random" behavior should be regarded as a fair coin: every time he answers a question, he has a 50% chance of saying DA and a 50% chance of saying JA.
