How do you plan to solve it?
module sr_latch_nor ( input S, input R, output reg Q, output reg Qn ); always @* begin if ((S == 1'b1) && (R == 1'b0)) begin Q = 1'b1; end if (R == 1'b1) begin Q = 1'b0; end Qn = ~Q; end endmodule