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(6,10).
next(10,11).
next(11,12).
next(12,13).
next(13,14).
next(14,15).
next(15,16).
next(13,17).
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(10,28).
next(28,29).
next(29,30).
next(30,31).
next(31,32).
next(32,33).
next(33,34).
next(34,35).
next(35,36).
next(36,37).
next(34,38).
next(38,39).
next(39,40).
next(33,41).
next(41,42).
next(42,43).
next(43,44).
next(44,45).
next(45,46).
next(46,47).
next(47,48).
next(30,49).
next(49,50).
next(50,51).
next(51,52).
next(52,53).
next(53,54).
next(54,55).
next(55,56).
next(56,57).
next(54,58).
next(58,59).
next(59,60).
next(53,61).
next(61,62).
next(62,63).
next(63,64).
next(64,65).
next(65,66).
next(66,67).
next(67,68).
doAt(startflow,3).
doAt(a7,4).
doAt(a8,5).
doAt(a21,6).
doAt(a25,7).
doAt(endflow,8).
doAt(a1,10).
doAt(a23,11).
doAt(a14,12).
doAt(a17,13).
doAt(a5,14).
doAt(endflow,15).
doAt(a16,17).
doAt(endflow,18).
doAt(a11,20).
doAt(a15,21).
doAt(a20,22).
doAt(a19,23).
doAt(a9,24).
doAt(a12,25).
doAt(endflow,26).
doAt(a6,28).
doAt(a4,29).
doAt(a3,30).
doAt(a18,31).
doAt(a10,32).
doAt(a14,33).
doAt(a17,34).
doAt(a5,35).
doAt(endflow,36).
doAt(a16,38).
doAt(endflow,39).
doAt(a11,41).
doAt(a15,42).
doAt(a20,43).
doAt(a19,44).
doAt(a9,45).
doAt(a12,46).
doAt(endflow,47).
doAt(a13,49).
doAt(a22,50).
doAt(a24,51).
doAt(a10,52).
doAt(a14,53).
doAt(a17,54).
doAt(a5,55).
doAt(endflow,56).
doAt(a16,58).
doAt(endflow,59).
doAt(a11,61).
doAt(a15,62).
doAt(a20,63).
doAt(a19,64).
doAt(a9,65).
doAt(a12,66).
doAt(endflow,67).
leftrightnexts(14,17).
leftrightnexts(13,20).
leftrightnexts(35,38).
leftrightnexts(34,41).
leftrightnexts(55,58).
leftrightnexts(54,61).
leftrightnexts(31,49).
leftrightnexts(11,28).
leftrightnexts(7,10).