Algorithm 4: F R U Ri Ui Fi
Goal: To form a yellow cross on the top face.
How to do it:
1) After completing step 3, you will always end up with having formed either a dot, a 9 o’clock, a horizontal line, or a cross on the top (yellow) face. Like these:
2) Perform Algorithm 4 repeatedly to form the cross (unless you’re lucky to already have the cross).