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(12,17).
next(17,18).
next(18,19).
next(19,20).
next(20,21).
next(21,22).
next(18,23).
next(23,24).
next(24,25).
next(25,26).
next(26,27).
next(27,28).
next(17,29).
next(29,30).
next(30,31).
next(31,32).
next(32,33).
next(29,34).
next(34,35).
next(35,36).
next(36,37).
next(37,38).
next(38,39).
next(39,40).
next(40,41).
next(35,42).
next(42,43).
next(43,44).
next(44,45).
next(45,46).
next(46,47).
next(47,48).
next(48,49).
next(49,50).
doAt(startflow,6).
doAt(a18,7).
doAt(a24,8).
doAt(a3,9).
doAt(a15,11).
doAt(a12,12).
doAt(a13,13).
doAt(a17,14).
doAt(endflow,15).
doAt(a25,17).
doAt(a8,18).
doAt(a10,19).
doAt(a17,20).
doAt(endflow,21).
doAt(a1,23).
doAt(a4,24).
doAt(a20,25).
doAt(a17,26).
doAt(endflow,27).
doAt(a23,29).
doAt(a21,30).
doAt(a17,31).
doAt(endflow,32).
doAt(a5,34).
doAt(a11,35).
doAt(a19,36).
doAt(a14,37).
doAt(a6,38).
doAt(a17,39).
doAt(endflow,40).
doAt(a9,42).
doAt(a22,43).
doAt(a2,44).
doAt(a16,45).
doAt(a14,46).
doAt(a6,47).
doAt(a17,48).
doAt(endflow,49).
subsAt(a15,10).
leftrightnexts(19,23).
leftrightnexts(36,42).
leftrightnexts(30,34).
leftrightnexts(18,29).
leftrightnexts(13,17).