next(1,2).
next(2,3).
next(3,4).
next(4,5).
next(5,6).
next(6,7).
next(7,8).
next(8,9).
next(9,10).
next(10,11).
next(11,12).
next(12,13).
next(13,14).
next(14,15).
next(15,16).
next(16,17).
next(17,18).
next(18,19).
next(12,20).
next(20,21).
next(21,22).
next(22,23).
next(23,24).
next(24,25).
next(25,26).
next(26,27).
next(27,28).
next(28,29).
next(29,30).
next(30,31).
next(25,32).
next(32,33).
next(33,34).
next(34,35).
next(35,36).
next(36,37).
doAt(startflow,8).
doAt(a13,10).
doAt(a4,12).
doAt(a2,14).
doAt(a1,15).
doAt(a12,16).
doAt(a7,17).
doAt(endflow,18).
doAt(a8,20).
doAt(a5,21).
doAt(a14,22).
doAt(a10,23).
doAt(a6,24).
doAt(a15,25).
doAt(a11,26).
doAt(a1,27).
doAt(a12,28).
doAt(a7,29).
doAt(endflow,30).
doAt(a9,32).
doAt(a1,33).
doAt(a12,34).
doAt(a7,35).
doAt(endflow,36).
compAt(a13,x8,9).
compAt(a1,x1,11).
subsAt(a2,13).
leftrightnexts(26,32).
leftrightnexts(13,20).