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(9,13).
next(13,14).
next(14,15).
next(15,16).
next(16,17).
next(17,18).
next(18,19).
next(19,20).
next(17,21).
next(21,22).
next(22,23).
next(23,24).
next(24,25).
next(25,26).
next(26,27).
next(27,28).
next(28,29).
next(26,30).
next(30,31).
next(31,32).
next(25,33).
next(33,34).
next(7,35).
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(45,46).
next(46,47).
next(47,48).
next(48,49).
next(49,50).
next(47,51).
next(51,52).
next(52,53).
next(53,54).
next(54,55).
next(55,56).
next(56,57).
next(57,58).
next(58,59).
next(56,60).
next(60,61).
next(61,62).
next(55,63).
next(63,64).
doAt(startflow,4).
doAt(a20,5).
doAt(a4,6).
doAt(a9,7).
doAt(a23,8).
doAt(a25,9).
doAt(a13,10).
doAt(endflow,11).
doAt(a1,13).
doAt(a22,14).
doAt(a10,15).
doAt(a15,16).
doAt(a21,17).
doAt(a11,18).
doAt(endflow,19).
doAt(a19,21).
doAt(a24,22).
doAt(a5,23).
doAt(a7,24).
doAt(a3,25).
doAt(a2,26).
doAt(a8,27).
doAt(endflow,28).
doAt(a6,30).
doAt(endflow,31).
doAt(endflow,33).
doAt(a12,35).
doAt(a16,36).
doAt(a17,37).
doAt(a14,38).
doAt(a25,39).
doAt(a13,40).
doAt(endflow,41).
doAt(a1,43).
doAt(a22,44).
doAt(a10,45).
doAt(a15,46).
doAt(a21,47).
doAt(a11,48).
doAt(endflow,49).
doAt(a19,51).
doAt(a24,52).
doAt(a5,53).
doAt(a7,54).
doAt(a3,55).
doAt(a2,56).
doAt(a8,57).
doAt(endflow,58).
doAt(a6,60).
doAt(endflow,61).
doAt(endflow,63).
leftrightnexts(27,30).
leftrightnexts(26,33).
leftrightnexts(18,21).
leftrightnexts(10,13).
leftrightnexts(57,60).
leftrightnexts(56,63).
leftrightnexts(48,51).
leftrightnexts(40,43).
leftrightnexts(8,35).