If J is to perform third, K must perform.

Two boys singers, F and G; two Girls singers, H and I; two boys comedians, J and K; and two girls comedians, L and M, are the eight actors who are to perform in a club on a certain night. Each actor is to perform alone and only once that night. The actors may perform in any order that conforms to the following restrictions: The performances by singers and the performances by comedians must exchange throughout the night. The first performance that night must be by a girl actor and the second performance by a boy actor. The final performance must, be by a boy singer.