Enter a permutation as comma-separated numbers (e.g., 1,3,2,6,7,5,4).
Click an upper-left elbow (╭─) and a lower-right blank (□) to attempt a droop move. Or, click a lower-right elbow (╯) and an upper-left blank (□) to attempt an undroop move. Standard droops can be initiated on either the BPD or its complement. K-droops can only be done on the BPD.