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(23,27).
next(27,28).
next(28,29).
next(22,30).
next(30,31).
next(31,32).
next(13,33).
next(33,34).
next(34,35).
next(35,36).
next(36,37).
next(37,38).
next(38,39).
next(39,40).
next(37,41).
next(41,42).
next(42,43).
next(43,44).
next(44,45).
next(45,46).
next(46,47).
next(44,48).
next(48,49).
next(49,50).
next(43,51).
next(51,52).
next(52,53).
next(33,54).
next(54,55).
next(55,56).
next(56,57).
next(57,58).
next(58,59).
next(59,60).
next(57,61).
next(61,62).
next(62,63).
next(63,64).
next(64,65).
next(65,66).
next(66,67).
next(64,68).
next(68,69).
next(69,70).
next(63,71).
next(71,72).
next(72,73).
doAt(startflow,3).
doAt(a12,5).
doAt(a6,6).
doAt(a3,7).
doAt(a20,8).
doAt(a7,9).
doAt(a25,10).
doAt(a18,11).
doAt(a9,12).
doAt(a22,13).
doAt(a16,14).
doAt(a17,15).
doAt(a15,16).
doAt(a24,17).
doAt(endflow,18).
doAt(a11,20).
doAt(a5,21).
doAt(a2,22).
doAt(a13,23).
doAt(a21,24).
doAt(endflow,25).
doAt(a14,27).
doAt(endflow,28).
doAt(a1,30).
doAt(endflow,31).
doAt(a4,33).
doAt(a19,34).
doAt(a10,35).
doAt(a17,36).
doAt(a15,37).
doAt(a24,38).
doAt(endflow,39).
doAt(a11,41).
doAt(a5,42).
doAt(a2,43).
doAt(a13,44).
doAt(a21,45).
doAt(endflow,46).
doAt(a14,48).
doAt(endflow,49).
doAt(a1,51).
doAt(endflow,52).
doAt(a8,54).
doAt(a10,55).
doAt(a17,56).
doAt(a15,57).
doAt(a24,58).
doAt(endflow,59).
doAt(a11,61).
doAt(a5,62).
doAt(a2,63).
doAt(a13,64).
doAt(a21,65).
doAt(endflow,66).
doAt(a14,68).
doAt(endflow,69).
doAt(a1,71).
doAt(endflow,72).
subsAt(a12,4).
leftrightnexts(24,27).
leftrightnexts(23,30).
leftrightnexts(17,20).
leftrightnexts(45,48).
leftrightnexts(44,51).
leftrightnexts(38,41).
leftrightnexts(65,68).
leftrightnexts(64,71).
leftrightnexts(58,61).
leftrightnexts(34,54).
leftrightnexts(14,33).