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(16,20).
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(25,29).
next(29,30).
next(30,31).
next(23,32).
next(32,33).
next(33,34).
next(34,35).
next(35,36).
next(36,37).
next(37,38).
next(38,39).
next(39,40).
next(40,41).
next(41,42).
next(39,43).
next(43,44).
next(44,45).
next(37,46).
next(46,47).
next(47,48).
next(48,49).
next(49,50).
next(47,51).
next(51,52).
next(52,53).
doAt(startflow,7).
doAt(a1,9).
doAt(a15,10).
doAt(a14,12).
doAt(a21,13).
doAt(a7,14).
doAt(a18,15).
doAt(a24,16).
doAt(a23,17).
doAt(endflow,18).
doAt(a6,20).
doAt(a12,21).
doAt(a11,22).
doAt(a22,23).
doAt(a8,24).
doAt(a3,25).
doAt(a2,26).
doAt(endflow,27).
doAt(a4,29).
doAt(endflow,30).
doAt(a13,32).
doAt(a20,33).
doAt(a16,34).
doAt(a19,35).
doAt(a9,36).
doAt(a5,37).
doAt(a17,38).
doAt(a3,39).
doAt(a2,40).
doAt(endflow,41).
doAt(a4,43).
doAt(endflow,44).
doAt(a25,46).
doAt(a3,47).
doAt(a2,48).
doAt(endflow,49).
doAt(a4,51).
doAt(endflow,52).
compAt(a21,x16,8).
subsAt(a14,11).
leftrightnexts(26,29).
leftrightnexts(40,43).
leftrightnexts(48,51).
leftrightnexts(38,46).
leftrightnexts(24,32).
leftrightnexts(17,20).