line(300,700,500,700);
line(300,700,300,500);
line(300,500,500,500);
line(500,500,500,700);
line(300,500,200,500);
line(200,500,200,300);
line(200,300,600,300);
line(600,500,600,300);
line(600,500,500,500);
line(300,300,300,500);
line(500,300,500,500);
line(300,300,300,100);
line(300,100,500,100);
line(500,100,500,300);