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 & ~K)begin Q <= Q; end else if(~J & K)begin Q <= 0; end else if(J & ~K)begin Q <= 1; end else if(J & K)begin Q <= ~Q; end end endmodule