How do you plan to solve it?
module jk_ff ( input CLK, input J, input K, output reg Q ); // Write your code here always @(posedge CLK) begin case({J,K}) 2'b00: Q <= Q; // hold 2'b01: Q <= 1'b0; // reset 2'b10: Q <= 1'b1; // set 2'b11: Q <= ~Q; // toggle endcase end endmodule