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(26,27). next(27,28). next(28,29). next(29,30). next(27,31). next(31,32). next(32,33). next(33,34). next(31,35). next(35,36). next(36,37). next(37,38). next(38,39). next(39,40). next(40,41). next(41,42). next(26,43). next(43,44). doAt(startflow,8). doAt(a21,9). doAt(a8,11). doAt(a2,13). doAt(a6,14). doAt(a16,15). doAt(a1,16). doAt(a3,17). doAt(a13,18). doAt(a22,19). doAt(endflow,20). doAt(a23,22). doAt(a14,23). doAt(a7,24). doAt(a5,25). doAt(a20,26). doAt(a15,27). doAt(a9,28). doAt(endflow,29). doAt(a19,31). doAt(a18,32). doAt(endflow,33). doAt(a4,35). doAt(a11,36). doAt(a10,37). doAt(a24,38). doAt(a17,39). doAt(a12,40). doAt(endflow,41). doAt(endflow,43). compAt(a1,x8,12). subsAt(a8,10). leftrightnexts(32,35). leftrightnexts(28,31). leftrightnexts(27,43). leftrightnexts(19,22).