Draw the Italian flag in the center of the canvas. It is 300 units wide and 200 units high.

The flag has three equal vertical stripes. From left to right, color them green, white, and red. Draw a black outline around each stripe.

Use a function named draw_rectangle(x0, y0, width, height, color) to draw each stripe. The x0 and y0 values mark the top-left corner of each rectangle.