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(5,17). next(17,18). next(18,19). next(19,20). next(20,21). next(21,22). next(22,23). next(23,24). next(21,25). next(25,26). next(26,27). next(4,28). 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(36,37). next(37,38). next(35,39). next(39,40). next(40,41). next(30,42). next(42,43). next(43,44). next(44,45). next(45,46). next(46,47). next(47,48). next(48,49). next(49,50). next(50,51). next(51,52). next(52,53). next(50,54). next(54,55). next(55,56). doAt(startflow,3). doAt(a12,4). doAt(a5,5). doAt(a20,6). doAt(a2,7). doAt(a8,8). doAt(a19,9). doAt(a13,10). doAt(a17,11). doAt(endflow,12). doAt(a9,14). doAt(endflow,15). doAt(a16,17). doAt(a2,18). doAt(a8,19). doAt(a19,20). doAt(a13,21). doAt(a17,22). doAt(endflow,23). doAt(a9,25). doAt(endflow,26). doAt(a14,28). doAt(a18,29). doAt(a1,30). doAt(a3,31). doAt(a2,32). doAt(a8,33). doAt(a19,34). doAt(a13,35). doAt(a17,36). doAt(endflow,37). doAt(a9,39). doAt(endflow,40). doAt(a6,42). doAt(a11,43). doAt(a10,44). doAt(a15,45). doAt(a4,46). doAt(a2,47). doAt(a8,48). doAt(a19,49). doAt(a13,50). doAt(a17,51). doAt(endflow,52). doAt(a9,54). doAt(endflow,55). leftrightnexts(11,14). leftrightnexts(22,25). leftrightnexts(6,17). leftrightnexts(36,39). leftrightnexts(51,54). leftrightnexts(31,42). leftrightnexts(5,28).