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(19,20). next(20,21). next(18,22). 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(30,31). next(31,32). next(29,33). next(33,34). next(34,35). next(35,36). next(36,37). next(37,38). next(38,39). next(22,40). next(40,41). doAt(startflow,5). doAt(a8,7). doAt(a20,8). doAt(a22,10). doAt(a1,11). doAt(a6,12). doAt(a5,13). doAt(a16,14). doAt(a4,15). doAt(a21,16). doAt(a11,17). doAt(a12,18). doAt(a14,19). doAt(endflow,20). doAt(a18,22). doAt(a9,23). doAt(a3,24). doAt(endflow,25). doAt(a25,27). doAt(a24,28). doAt(a7,29). doAt(a15,30). doAt(endflow,31). doAt(a10,33). doAt(a2,34). doAt(a13,35). doAt(a19,36). doAt(a23,37). doAt(endflow,38). doAt(endflow,40). compAt(a22,x16,9). subsAt(a8,6). leftrightnexts(30,33). leftrightnexts(24,27). leftrightnexts(23,40). leftrightnexts(19,22).