next(1,2).
next(2,3).
next(3,4).
next(4,5).
next(5,6).
next(6,7).
next(4,8).
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(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(28,29).
next(26,30).
next(30,31).
next(31,32).
next(25,33).
next(33,34).
next(34,35).
next(18,36).
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(44,48).
next(48,49).
next(49,50).
next(43,51).
next(51,52).
next(52,53).
doAt(startflow,3).
doAt(a7,4).
doAt(a4,5).
doAt(endflow,6).
doAt(a22,8).
doAt(a18,9).
doAt(a10,10).
doAt(a1,11).
doAt(a2,12).
doAt(a8,13).
doAt(a24,14).
doAt(a15,15).
doAt(a25,16).
doAt(a17,17).
doAt(a19,18).
doAt(a12,19).
doAt(a3,20).
doAt(a5,21).
doAt(a9,22).
doAt(endflow,23).
doAt(a6,25).
doAt(a23,26).
doAt(a16,27).
doAt(endflow,28).
doAt(a21,30).
doAt(endflow,31).
doAt(a13,33).
doAt(endflow,34).
doAt(a14,36).
doAt(a20,37).
doAt(a3,38).
doAt(a5,39).
doAt(a9,40).
doAt(endflow,41).
doAt(a6,43).
doAt(a23,44).
doAt(a16,45).
doAt(endflow,46).
doAt(a21,48).
doAt(endflow,49).
doAt(a13,51).
doAt(endflow,52).
leftrightnexts(27,30).
leftrightnexts(26,33).
leftrightnexts(22,25).
leftrightnexts(45,48).
leftrightnexts(44,51).
leftrightnexts(40,43).
leftrightnexts(19,36).
leftrightnexts(5,8).