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(14,18).
next(18,19).
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(27,28).
next(20,29).
next(29,30).
next(18,31).
next(31,32).
next(32,33).
next(33,34).
next(34,35).
next(35,36).
next(36,37).
next(37,38).
next(35,39).
next(39,40).
next(40,41).
next(41,42).
next(34,43).
next(43,44).
next(32,45).
next(45,46).
next(46,47).
next(47,48).
next(48,49).
next(49,50).
next(50,51).
next(48,52).
next(52,53).
next(53,54).
next(54,55).
next(47,56).
next(56,57).
doAt(startflow,3).
doAt(a12,4).
doAt(a5,5).
doAt(a24,6).
doAt(a15,7).
doAt(a6,8).
doAt(a13,9).
doAt(a2,10).
doAt(a21,11).
doAt(a1,12).
doAt(a22,13).
doAt(a14,14).
doAt(a16,15).
doAt(endflow,16).
doAt(a8,18).
doAt(a25,19).
doAt(a10,20).
doAt(a20,21).
doAt(a18,22).
doAt(endflow,23).
doAt(a19,25).
doAt(a4,26).
doAt(endflow,27).
doAt(endflow,29).
doAt(a17,31).
doAt(a3,32).
doAt(a9,33).
doAt(a10,34).
doAt(a20,35).
doAt(a18,36).
doAt(endflow,37).
doAt(a19,39).
doAt(a4,40).
doAt(endflow,41).
doAt(endflow,43).
doAt(a7,45).
doAt(a23,46).
doAt(a10,47).
doAt(a20,48).
doAt(a18,49).
doAt(endflow,50).
doAt(a19,52).
doAt(a4,53).
doAt(endflow,54).
doAt(endflow,56).
leftrightnexts(22,25).
leftrightnexts(21,29).
leftrightnexts(36,39).
leftrightnexts(35,43).
leftrightnexts(49,52).
leftrightnexts(48,56).
leftrightnexts(33,45).
leftrightnexts(19,31).
leftrightnexts(15,18).