//typedef enum {ZERO,UN,DEUX} state_t;

module concret(clk,i);
input clk;

reg p;
reg q;
input i;
reg[1:0] state;

initial 
begin
p = 0;
q = 0;
state[1:0] = 0;
end

always @(posedge clk)
begin
case(state)
	0 :
		if(i == 1)
		begin
			state[1:0] = 1;
			p = 0;
			q = 1;
		end
		else
		begin
			state[1:0] = 2;
			p = 1;
			q = 0;
		end
    1 :  if(i == 1)
		begin
			state[1:0] = 1;
			p = 0;
			q = 1;
		end
		else
		begin
			state[1:0] = 3;
			p = 1;
			q = 1;
		end
    2 :  if(i == 1)
		begin
			state[1:0] = 2;
			p = 1;
			q = 0;
		end
		else
		begin
			state[1:0] = 3;
			p = 1;
			q = 1;
		end
    3 :  if(i == 1)
		begin
			state[1:0] = 2;
			p = 1;
			q = 0;
		end
		else
		begin
			state[1:0] = 3;
			p = 1;
			q = 1;
		end

endcase	

end


endmodule