module Sys (KEY, LEDR, SW, HEX1,HEX2,HEX3,HEX0 );
input[0:2] KEY;
input [9:0] SW ;
output [9:0] LEDR;
output[6:0] HEX0;
output[6:0] HEX1;
output[6:0] HEX2;
output[6:0] HEX3;

reg [9:0]out;
reg [6:0]o;

assign LEDR = out;
assign HEX3 = o;


always
begin

if (KEY[0] == 0)
	begin
	out <= SW[9:5] + SW[4:0];
	o <= 7'b1111111;
	end
else if (KEY[1]== 0 && SW[9:5] > SW[4:0])
	begin
	out <= SW[9:5] - SW[4:0];
	o <= 7'b1111111;
	end
else if (KEY[1]== 0 && SW[9:5] < SW[4:0])
	begin
	out <= SW[4:0] - SW[9:5];
	o <= 7'b0111111;
	end
else if (KEY[2] == 0)
	begin
	out <= SW[9:5] * SW[4:0];
	o <= 7'b1111111;
	end
end

zamiana ((LEDR / 10) % 10, HEX1);
zamiana ((LEDR /100) % 10, HEX2);
zamiana (LEDR % 10, HEX0);
endmodule

module zamiana (in,ou);
input [3:0] in;
output reg [6:0] ou;

always
begin
    if (in == 4'd0)
			ou = 7'b1000000;
   else if (in == 4'd1)
			ou = 7'b1111001;
   else if (in == 4'd2)
			ou = 7'b0100100;
   else if (in == 4'd3)
        ou = 7'b0110000;
   else if (in == 4'd4)
        ou = 7'b0011001;
   else if (in == 4'd5)
        ou = 7'b0010010;
   else if (in == 4'd6)
        ou = 7'b0000010;
   else if (in == 4'd7)
	     ou = 7'b1111000;
   else if (in == 4'd8)
        ou = 7'b0000000;
   else if (in == 4'd9)
        ou = 7'b0010000;
	end
endmodule