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(8,12).
next(12,13).
next(13,14).
next(14,15).
next(12,16).
next(16,17).
next(17,18).
next(18,19).
next(19,20).
next(20,21).
next(21,22).
next(19,23).
next(23,24).
next(24,25).
next(25,26).
next(26,27).
next(24,28).
next(28,29).
next(29,30).
next(30,31).
next(16,32).
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(42,43).
next(40,44).
next(44,45).
next(45,46).
next(46,47).
next(47,48).
next(45,49).
next(49,50).
next(50,51).
next(51,52).
doAt(startflow,3).
doAt(a22,5).
doAt(a3,6).
doAt(a16,7).
doAt(a1,8).
doAt(a7,9).
doAt(endflow,10).
doAt(a17,12).
doAt(a14,13).
doAt(endflow,14).
doAt(a19,16).
doAt(a18,17).
doAt(a5,18).
doAt(a11,19).
doAt(a6,20).
doAt(endflow,21).
doAt(a2,23).
doAt(a25,24).
doAt(a13,25).
doAt(endflow,26).
doAt(a21,28).
doAt(a9,29).
doAt(endflow,30).
doAt(a23,32).
doAt(a15,33).
doAt(a4,34).
doAt(a24,35).
doAt(a20,36).
doAt(a12,37).
doAt(a10,38).
doAt(a5,39).
doAt(a11,40).
doAt(a6,41).
doAt(endflow,42).
doAt(a2,44).
doAt(a25,45).
doAt(a13,46).
doAt(endflow,47).
doAt(a21,49).
doAt(a9,50).
doAt(endflow,51).
subsAt(a22,4).
leftrightnexts(25,28).
leftrightnexts(20,23).
leftrightnexts(46,49).
leftrightnexts(41,44).
leftrightnexts(17,32).
leftrightnexts(13,16).
leftrightnexts(9,12).