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(14,19). next(19,20). next(20,21). next(21,22). next(22,23). next(23,24). next(24,25). next(25,26). next(26,27). next(23,28). next(28,29). next(29,30). next(30,31). next(31,32). next(28,33). next(33,34). next(34,35). next(35,36). next(36,37). next(37,38). next(38,39). next(35,40). next(40,41). next(41,42). next(42,43). doAt(startflow,4). doAt(a18,6). doAt(a7,7). doAt(a20,8). doAt(a4,9). doAt(a8,10). doAt(a12,11). doAt(a6,12). doAt(a11,13). doAt(a5,14). doAt(a23,15). doAt(a24,16). doAt(endflow,17). doAt(a16,19). doAt(a25,20). doAt(a2,21). doAt(a15,22). doAt(a22,23). doAt(a3,24). doAt(a24,25). doAt(endflow,26). doAt(a17,28). doAt(a19,29). doAt(a24,30). doAt(endflow,31). doAt(a21,33). doAt(a9,34). doAt(a14,35). doAt(a10,36). doAt(a24,37). doAt(endflow,38). doAt(a13,40). doAt(a24,41). doAt(endflow,42). subsAt(a18,5). leftrightnexts(36,40). leftrightnexts(29,33). leftrightnexts(24,28). leftrightnexts(15,19).