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(7,12).
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(16,21).
next(21,22).
next(22,23).
next(23,24).
next(24,25).
next(21,26).
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(31,36).
next(36,37).
next(37,38).
next(38,39).
next(28,40).
next(40,41).
next(41,42).
next(42,43).
next(43,44).
next(44,45).
next(45,46).
next(46,47).
next(43,48).
next(48,49).
next(49,50).
next(50,51).
doAt(startflow,3).
doAt(a21,4).
doAt(a6,5).
doAt(a4,6).
doAt(a10,7).
doAt(a8,8).
doAt(a14,9).
doAt(endflow,10).
doAt(a5,12).
doAt(a9,13).
doAt(a22,14).
doAt(a17,15).
doAt(a12,16).
doAt(a20,17).
doAt(a14,18).
doAt(endflow,19).
doAt(a25,21).
doAt(a11,22).
doAt(a14,23).
doAt(endflow,24).
doAt(a24,26).
doAt(a1,27).
doAt(a7,28).
doAt(a3,29).
doAt(a15,30).
doAt(a16,31).
doAt(a13,32).
doAt(a14,33).
doAt(endflow,34).
doAt(a2,36).
doAt(a14,37).
doAt(endflow,38).
doAt(a23,40).
doAt(a18,41).
doAt(a15,42).
doAt(a16,43).
doAt(a13,44).
doAt(a14,45).
doAt(endflow,46).
doAt(a2,48).
doAt(a14,49).
doAt(endflow,50).
leftrightnexts(32,36).
leftrightnexts(44,48).
leftrightnexts(29,40).
leftrightnexts(22,26).
leftrightnexts(17,21).
leftrightnexts(8,12).