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(14,18).
next(18,19).
next(19,20).
next(20,21).
next(21,22).
next(22,23).
next(23,24).
next(24,25).
next(25,26).
next(23,27).
next(27,28).
next(28,29).
next(29,30).
next(27,31).
next(31,32).
next(32,33).
next(19,34).
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(43,44).
next(41,45).
next(45,46).
next(46,47).
next(47,48).
next(45,49).
next(49,50).
next(50,51).
doAt(startflow,4).
doAt(a22,6).
doAt(a23,8).
doAt(a10,9).
doAt(a25,10).
doAt(a21,11).
doAt(a16,12).
doAt(a7,13).
doAt(a15,14).
doAt(a14,15).
doAt(endflow,16).
doAt(a17,18).
doAt(a4,19).
doAt(a12,20).
doAt(a8,21).
doAt(a20,22).
doAt(a1,23).
doAt(a2,24).
doAt(endflow,25).
doAt(a13,27).
doAt(a6,28).
doAt(endflow,29).
doAt(a5,31).
doAt(endflow,32).
doAt(a3,34).
doAt(a9,35).
doAt(a19,36).
doAt(a11,37).
doAt(a24,38).
doAt(a8,39).
doAt(a20,40).
doAt(a1,41).
doAt(a2,42).
doAt(endflow,43).
doAt(a13,45).
doAt(a6,46).
doAt(endflow,47).
doAt(a5,49).
doAt(endflow,50).
compAt(a22,x1,5).
compAt(a23,x21,7).
leftrightnexts(28,31).
leftrightnexts(24,27).
leftrightnexts(46,49).
leftrightnexts(42,45).
leftrightnexts(20,34).
leftrightnexts(15,18).