How do you plan to solve it?
module jk_ff ( input CLK, input J, input K, output reg Q ); always @(posedge CLK) begin if(J == 0 && K == 0) Q <= Q; else if (J == 0 && K == 1) Q <= 1'b0; else if (J == 1 && K == 0) Q <= 1'b1; else Q <= ~Q; end endmodule