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(15,24).
next(24,25).
next(8,26).
next(26,27).
next(27,28).
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(40,41).
next(33,42).
next(42,43).
next(27,44).
next(44,45).
next(45,46).
next(46,47).
next(47,48).
next(48,49).
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(57,58).
next(55,59).
next(59,60).
next(60,61).
next(61,62).
next(54,63).
next(63,64).
doAt(startflow,3).
doAt(a13,5).
doAt(a6,6).
doAt(a18,7).
doAt(a25,8).
doAt(a21,9).
doAt(a10,10).
doAt(a14,11).
doAt(a11,12).
doAt(a5,13).
doAt(a24,14).
doAt(a17,15).
doAt(a3,16).
doAt(a12,17).
doAt(endflow,18).
doAt(a16,20).
doAt(a4,21).
doAt(endflow,22).
doAt(endflow,24).
doAt(a1,26).
doAt(a7,27).
doAt(a15,28).
doAt(a14,29).
doAt(a11,30).
doAt(a5,31).
doAt(a24,32).
doAt(a17,33).
doAt(a3,34).
doAt(a12,35).
doAt(endflow,36).
doAt(a16,38).
doAt(a4,39).
doAt(endflow,40).
doAt(endflow,42).
doAt(a9,44).
doAt(a23,45).
doAt(a20,46).
doAt(a19,47).
doAt(a22,48).
doAt(a2,49).
doAt(a14,50).
doAt(a11,51).
doAt(a5,52).
doAt(a24,53).
doAt(a17,54).
doAt(a3,55).
doAt(a12,56).
doAt(endflow,57).
doAt(a16,59).
doAt(a4,60).
doAt(endflow,61).
doAt(endflow,63).
subsAt(a13,4).
leftrightnexts(17,20).
leftrightnexts(16,24).
leftrightnexts(35,38).
leftrightnexts(34,42).
leftrightnexts(56,59).
leftrightnexts(55,63).
leftrightnexts(28,44).
leftrightnexts(9,26).