10 FOR W=1 TO 4
20 FOR I=0 TO 63 STEP 2*W
30 FOR J=1 TO W
40 FOR K=43-11*(W-1) TO 33-11*(W-1) STEP -1
50 PLOT I+J,K
60 NEXT K
70 NEXT J
80 NEXT I
90 NEXT W