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(10,14).
next(14,15).
next(15,16).
next(16,17).
next(17,18).
next(15,19).
next(19,20).
next(20,21).
next(21,22).
next(8,23).
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(28,32).
next(32,33).
next(33,34).
next(34,35).
next(35,36).
next(33,37).
next(37,38).
next(38,39).
next(39,40).
next(26,41).
next(41,42).
next(42,43).
next(43,44).
next(44,45).
next(45,46).
next(46,47).
next(47,48).
next(48,49).
next(46,50).
next(50,51).
next(51,52).
next(52,53).
next(53,54).
next(51,55).
next(55,56).
next(56,57).
next(57,58).
next(25,59).
next(59,60).
next(60,61).
next(61,62).
next(62,63).
next(60,64).
next(64,65).
next(65,66).
next(66,67).
next(67,68).
next(65,69).
next(69,70).
next(70,71).
next(71,72).
doAt(startflow,3).
doAt(a17,4).
doAt(a22,5).
doAt(a21,6).
doAt(a11,7).
doAt(a12,8).
doAt(a19,9).
doAt(a18,10).
doAt(a2,11).
doAt(endflow,12).
doAt(a25,14).
doAt(a7,15).
doAt(a10,16).
doAt(endflow,17).
doAt(a6,19).
doAt(a20,20).
doAt(endflow,21).
doAt(a3,23).
doAt(a9,24).
doAt(a5,25).
doAt(a8,26).
doAt(a23,27).
doAt(a18,28).
doAt(a2,29).
doAt(endflow,30).
doAt(a25,32).
doAt(a7,33).
doAt(a10,34).
doAt(endflow,35).
doAt(a6,37).
doAt(a20,38).
doAt(endflow,39).
doAt(a14,41).
doAt(a13,42).
doAt(a16,43).
doAt(a1,44).
doAt(a4,45).
doAt(a18,46).
doAt(a2,47).
doAt(endflow,48).
doAt(a25,50).
doAt(a7,51).
doAt(a10,52).
doAt(endflow,53).
doAt(a6,55).
doAt(a20,56).
doAt(endflow,57).
doAt(a24,59).
doAt(a18,60).
doAt(a2,61).
doAt(endflow,62).
doAt(a25,64).
doAt(a7,65).
doAt(a10,66).
doAt(endflow,67).
doAt(a6,69).
doAt(a20,70).
doAt(endflow,71).
leftrightnexts(16,19).
leftrightnexts(11,14).
leftrightnexts(34,37).
leftrightnexts(29,32).
leftrightnexts(52,55).
leftrightnexts(47,50).
leftrightnexts(27,41).
leftrightnexts(66,69).
leftrightnexts(61,64).
leftrightnexts(26,59).
leftrightnexts(9,23).