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(11,15).
next(15,16).
next(16,17).
next(17,18).
next(15,19).
next(19,20).
next(20,21).
next(21,22).
next(22,23).
next(23,24).
next(21,25).
next(25,26).
next(26,27).
next(20,28).
next(28,29).
next(29,30).
next(8,31).
next(31,32).
next(32,33).
next(33,34).
next(34,35).
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(43,47).
next(47,48).
next(48,49).
next(49,50).
next(50,51).
next(51,52).
next(49,53).
next(53,54).
next(54,55).
next(48,56).
next(56,57).
next(57,58).
doAt(startflow,3).
doAt(a8,4).
doAt(a4,5).
doAt(a9,6).
doAt(a13,7).
doAt(a20,8).
doAt(a22,9).
doAt(a14,10).
doAt(a7,11).
doAt(a24,12).
doAt(endflow,13).
doAt(a12,15).
doAt(a15,16).
doAt(endflow,17).
doAt(a18,19).
doAt(a11,20).
doAt(a21,21).
doAt(a2,22).
doAt(endflow,23).
doAt(a1,25).
doAt(endflow,26).
doAt(a16,28).
doAt(endflow,29).
doAt(a5,31).
doAt(a3,32).
doAt(a17,33).
doAt(a10,34).
doAt(a25,35).
doAt(a6,36).
doAt(a19,37).
doAt(a14,38).
doAt(a7,39).
doAt(a24,40).
doAt(endflow,41).
doAt(a12,43).
doAt(a15,44).
doAt(endflow,45).
doAt(a18,47).
doAt(a11,48).
doAt(a21,49).
doAt(a2,50).
doAt(endflow,51).
doAt(a1,53).
doAt(endflow,54).
doAt(a16,56).
doAt(endflow,57).
leftrightnexts(22,25).
leftrightnexts(21,28).
leftrightnexts(16,19).
leftrightnexts(12,15).
leftrightnexts(50,53).
leftrightnexts(49,56).
leftrightnexts(44,47).
leftrightnexts(40,43).
leftrightnexts(9,31).