17. Binary to Gray Code Converter

How do you plan to solve it?

/*Write your code here*/
module bin2gray4 (
    input [3:0] bin_in,
    output reg [3:0] gray_out
);

    always @ (*) begin
        case (bin_in)
        0:gray_out = 0;
        1:gray_out = 1;
        2:gray_out = 3;
        3:gray_out = 2;
        4:gray_out = 6;
        5:gray_out = 7;
        6:gray_out = 5;
        7:gray_out = 4;
        8:gray_out = 12;
        9:gray_out = 13;
        10:gray_out = 15;
        11:gray_out = 14;
        12:gray_out = 10;
        13:gray_out = 11;
        14:gray_out = 9;
        15:gray_out = 8;
        endcase
    end

endmodule