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(13,18). next(18,19). next(19,20). next(20,21). next(21,22). next(22,23). next(23,24). next(19,25). next(25,26). next(26,27). next(27,28). next(28,29). next(29,30). next(30,31). next(31,32). next(27,33). next(33,34). next(34,35). next(35,36). next(36,37). next(37,38). next(38,39). next(34,40). next(40,41). next(41,42). next(42,43). next(43,44). next(44,45). next(45,46). next(41,47). next(47,48). next(48,49). next(49,50). next(50,51). next(51,52). next(52,53). next(53,54). next(54,55). doAt(startflow,7). doAt(a3,11). doAt(a21,12). doAt(a6,13). doAt(a18,14). doAt(a19,15). doAt(endflow,16). doAt(a7,18). doAt(a11,19). doAt(a4,20). doAt(a19,22). doAt(endflow,23). doAt(a15,25). doAt(a10,26). doAt(a25,27). doAt(a2,28). doAt(a19,30). doAt(endflow,31). doAt(a20,33). doAt(a1,34). doAt(a16,35). doAt(a19,37). doAt(endflow,38). doAt(a22,40). doAt(a24,41). doAt(a8,43). doAt(a19,44). doAt(endflow,45). doAt(a12,47). doAt(a23,48). doAt(a14,49). doAt(a5,50). doAt(a17,51). doAt(a9,52). doAt(a19,53). doAt(endflow,54). compAt(a21,x4,9). compAt(a21,x12,10). compAt(a18,x8,21). compAt(a18,x8,29). compAt(a18,x8,36). compAt(a18,x8,42). subsAt(a3,8). leftrightnexts(42,47). leftrightnexts(35,40). leftrightnexts(28,33). leftrightnexts(20,25). leftrightnexts(14,18).