The three parties are Party A, Party B and Party C respectively. If you ask three people in turn, answer the truth with t and the lie with f, then:

A T F F

B T T F

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It can be seen that when A answers the lie F and B answers the truth T (their answers are different), only ask twice to know the answer, and B answers the truth.

When A and B agree and C disagree, we can't tell the answer. They may all tell the truth or lie, but we can't tell the truth.

In fact, we can ignore C, because his answer is always the antonym of B.

If you don't ask three people in sequence, according to the conditions of the topic, it is unclear whether B (or C) is true first.