1 print"S":a=1:b=1
2 forz=1to3:readx:y=18
3 fors=1to36:poke214,y:print:poke211,x:print"*":x=x+a:y=y-b
4 ifx<1orx>17thena=-a
5 ify<1ory>17thenb=-b
6 next:next:data3,9,15
