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(10,14). next(14,15). next(15,16). next(16,17). next(17,18). next(18,19). next(19,20). next(20,21). next(21,22). next(22,23). next(20,24). next(24,25). next(25,26). next(26,27). next(24,28). next(28,29). next(29,30). next(30,31). next(31,32). next(32,33). next(33,34). next(34,35). next(35,36). next(32,37). next(37,38). next(38,39). next(39,40). next(30,41). next(41,42). next(42,43). next(43,44). next(44,45). next(45,46). next(42,47). next(47,48). next(48,49). next(49,50). doAt(startflow,4). doAt(a6,5). doAt(a9,8). doAt(a14,9). doAt(a2,10). doAt(a25,11). doAt(endflow,12). doAt(a3,14). doAt(a19,15). doAt(a24,16). doAt(a18,17). doAt(a5,18). doAt(a17,19). doAt(a13,20). doAt(a20,21). doAt(endflow,22). doAt(a11,24). doAt(a22,25). doAt(endflow,26). doAt(a7,28). doAt(a23,29). doAt(a8,30). doAt(a4,31). doAt(a1,32). doAt(a10,33). doAt(a12,34). doAt(endflow,35). doAt(a16,37). doAt(a12,38). doAt(endflow,39). doAt(a15,41). doAt(a1,42). doAt(a10,43). doAt(a12,44). doAt(endflow,45). doAt(a16,47). doAt(a12,48). doAt(endflow,49). compAt(a9,x7,7). subsAt(a9,6). leftrightnexts(33,37). leftrightnexts(43,47). leftrightnexts(31,41). leftrightnexts(25,28). leftrightnexts(21,24). leftrightnexts(11,14).