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We need to arrange $6$ students into $3$ different queues $($queue A$,$ queue B$,$ queue C$).$ The number of students in the queues can be different, any of the three queues can be empty, and the order of the students within a queue matters $.$ How many ways to form the queues? Answer as an expression; final answer is not needed. You can type the expression as in C$/$C$++.$