There is a blank disc( like a CD). You are given two colors of paint (black and white). A sensor can recognize the color painted on the disc and produ

There is a blank disc( like a CD). You are given two colors of paint (black and white). A sensor can recognize the color painted on the disc and produce an output. Paint the disc in a way such that you can find the direction of rotation by looking at the output.
Paint like WWBWBB
After 2 ww, if it is BW, one direction
After 2 ww if it is BB, the other direction