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(8,13). 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(17,22). 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(30,31). next(31,32). next(32,33). next(29,34). next(34,35). next(35,36). next(36,37). next(37,38). next(38,39). next(25,40). next(40,41). next(41,42). next(42,43). next(43,44). next(44,45). next(45,46). next(46,47). next(43,48). next(48,49). next(49,50). next(50,51). next(51,52). next(52,53). doAt(startflow,4). doAt(a21,6). doAt(a19,7). doAt(a18,8). doAt(a7,9). doAt(a8,10). doAt(endflow,11). doAt(a6,13). doAt(a12,14). doAt(a15,15). doAt(a3,16). doAt(a20,17). doAt(a5,18). doAt(a8,19). doAt(endflow,20). doAt(a14,22). doAt(a13,23). doAt(a25,24). doAt(a9,25). doAt(a23,26). doAt(a2,27). doAt(a16,28). doAt(a22,29). doAt(a10,30). doAt(a8,31). doAt(endflow,32). doAt(a17,34). doAt(a1,35). doAt(a4,36). doAt(a8,37). doAt(endflow,38). doAt(a24,40). doAt(a2,41). doAt(a16,42). doAt(a22,43). doAt(a10,44). doAt(a8,45). doAt(endflow,46). doAt(a17,48). doAt(a1,49). doAt(a4,50). doAt(a8,51). doAt(endflow,52). compAt(a21,x4,5). leftrightnexts(30,34). leftrightnexts(44,48). leftrightnexts(26,40). leftrightnexts(18,22). leftrightnexts(9,13).