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(8,14).
next(14,15).
next(15,16).
next(16,17).
next(17,18).
next(18,19).
next(14,20).
next(20,21).
next(21,22).
next(22,23).
next(23,24).
next(24,25).
next(25,26).
next(26,27).
next(22,28).
next(28,29).
next(29,30).
next(30,31).
next(31,32).
next(32,33).
next(33,34).
next(34,35).
next(35,36).
next(36,37).
next(32,38).
next(38,39).
next(39,40).
next(40,41).
next(41,42).
next(42,43).
next(38,44).
next(44,45).
next(45,46).
next(46,47).
next(47,48).
next(48,49).
next(49,50).
doAt(startflow,3).
doAt(a21,5).
doAt(a10,6).
doAt(a15,7).
doAt(a1,8).
doAt(a3,9).
doAt(a6,10).
doAt(a8,11).
doAt(endflow,12).
doAt(a24,14).
doAt(a23,15).
doAt(a6,16).
doAt(a8,17).
doAt(endflow,18).
doAt(a25,20).
doAt(a7,21).
doAt(a11,22).
doAt(a4,23).
doAt(a6,24).
doAt(a8,25).
doAt(endflow,26).
doAt(a9,28).
doAt(a5,29).
doAt(a12,30).
doAt(a17,31).
doAt(a16,32).
doAt(a2,33).
doAt(a6,34).
doAt(a8,35).
doAt(endflow,36).
doAt(a18,38).
doAt(a13,39).
doAt(a6,40).
doAt(a8,41).
doAt(endflow,42).
doAt(a20,44).
doAt(a19,45).
doAt(a22,46).
doAt(a6,47).
doAt(a8,48).
doAt(endflow,49).
subsAt(a21,4).
leftrightnexts(39,44).
leftrightnexts(33,38).
leftrightnexts(23,28).
leftrightnexts(15,20).
leftrightnexts(9,14).