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(14,18).
next(18,19).
next(19,20).
next(20,21).
next(18,22).
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(31,32).
next(28,33).
next(33,34).
next(34,35).
next(35,36).
next(36,37).
next(4,38).
next(38,39).
next(39,40).
next(40,41).
next(41,42).
next(42,43).
next(43,44).
next(44,45).
next(42,46).
next(46,47).
next(47,48).
next(48,49).
next(46,50).
next(50,51).
next(51,52).
next(52,53).
next(50,54).
next(54,55).
next(55,56).
next(56,57).
next(57,58).
next(58,59).
next(59,60).
next(60,61).
next(61,62).
next(62,63).
next(63,64).
next(60,65).
next(65,66).
next(66,67).
next(67,68).
next(68,69).
doAt(startflow,3).
doAt(a24,4).
doAt(a12,5).
doAt(a21,6).
doAt(a25,7).
doAt(a23,8).
doAt(a18,9).
doAt(a4,10).
doAt(a13,11).
doAt(endflow,12).
doAt(a9,14).
doAt(a6,15).
doAt(endflow,16).
doAt(a7,18).
doAt(a20,19).
doAt(endflow,20).
doAt(a22,22).
doAt(a1,23).
doAt(a15,24).
doAt(a11,25).
doAt(a5,26).
doAt(a19,27).
doAt(a14,28).
doAt(a16,29).
doAt(a10,30).
doAt(endflow,31).
doAt(a17,33).
doAt(a8,34).
doAt(a10,35).
doAt(endflow,36).
doAt(a3,38).
doAt(a25,39).
doAt(a23,40).
doAt(a18,41).
doAt(a4,42).
doAt(a13,43).
doAt(endflow,44).
doAt(a9,46).
doAt(a6,47).
doAt(endflow,48).
doAt(a7,50).
doAt(a20,51).
doAt(endflow,52).
doAt(a22,54).
doAt(a1,55).
doAt(a15,56).
doAt(a11,57).
doAt(a5,58).
doAt(a19,59).
doAt(a14,60).
doAt(a16,61).
doAt(a10,62).
doAt(endflow,63).
doAt(a17,65).
doAt(a8,66).
doAt(a10,67).
doAt(endflow,68).
leftrightnexts(29,33).
leftrightnexts(19,22).
leftrightnexts(15,18).
leftrightnexts(11,14).
leftrightnexts(61,65).
leftrightnexts(51,54).
leftrightnexts(47,50).
leftrightnexts(43,46).
leftrightnexts(5,38).