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(17,18).
next(18,19).
next(15,20).
next(20,21).
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(27,32).
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(36,41).
next(41,42).
next(42,43).
next(43,44).
next(44,45).
next(45,46).
next(14,47).
next(47,48).
next(48,49).
next(49,50).
doAt(startflow,6).
doAt(a7,8).
doAt(a18,11).
doAt(a10,12).
doAt(a14,13).
doAt(a13,14).
doAt(a12,15).
doAt(a23,16).
doAt(a25,17).
doAt(endflow,18).
doAt(a9,20).
doAt(a11,21).
doAt(a6,22).
doAt(a25,23).
doAt(endflow,24).
doAt(a21,26).
doAt(a8,27).
doAt(a16,28).
doAt(a25,29).
doAt(endflow,30).
doAt(a19,32).
doAt(a15,33).
doAt(a4,34).
doAt(a17,35).
doAt(a24,36).
doAt(a1,37).
doAt(a25,38).
doAt(endflow,39).
doAt(a2,41).
doAt(a3,42).
doAt(a5,43).
doAt(a25,44).
doAt(endflow,45).
doAt(a20,47).
doAt(a25,48).
doAt(endflow,49).
compAt(a14,x21,10).
subsAt(a7,7).
subsAt(a18,9).
leftrightnexts(37,41).
leftrightnexts(28,32).
leftrightnexts(22,26).
leftrightnexts(16,20).
leftrightnexts(15,47).