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(12,16). next(16,17). next(17,18). next(18,19). next(19,20). next(20,21). next(11,22). next(22,23). next(23,24). next(24,25). next(25,26). next(26,27). next(27,28). next(28,29). next(26,30). next(30,31). next(31,32). next(32,33). next(33,34). next(34,35). next(32,36). next(36,37). next(37,38). next(38,39). next(31,40). next(40,41). next(41,42). next(42,43). doAt(startflow,6). doAt(a15,7). doAt(a7,8). doAt(a12,10). doAt(a20,11). doAt(a14,12). doAt(a17,13). doAt(endflow,14). doAt(a13,16). doAt(a5,17). doAt(a16,18). doAt(a4,19). doAt(endflow,20). doAt(a23,22). doAt(a21,23). doAt(a10,24). doAt(a9,25). doAt(a19,26). doAt(a6,27). doAt(endflow,28). doAt(a2,30). doAt(a11,31). doAt(a3,32). doAt(a24,33). doAt(endflow,34). doAt(a25,36). doAt(a8,37). doAt(endflow,38). doAt(a22,40). doAt(a1,41). doAt(endflow,42). compAt(a12,x15,9). leftrightnexts(13,16). leftrightnexts(33,36). leftrightnexts(32,40). leftrightnexts(27,30). leftrightnexts(12,22).