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(15,20). next(20,21). next(21,22). next(22,23). next(23,24). next(24,25). next(25,26). next(26,27). next(23,28). 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(28,39). next(39,40). next(40,41). next(41,42). next(42,43). doAt(startflow,4). doAt(a10,6). doAt(a21,7). doAt(a19,8). doAt(a12,9). doAt(a5,10). doAt(a13,11). doAt(a18,12). doAt(a1,13). doAt(a17,14). doAt(a15,15). doAt(a22,16). doAt(a3,17). doAt(endflow,18). doAt(a25,20). doAt(a9,21). doAt(a2,22). doAt(a14,23). doAt(a11,24). doAt(a3,25). doAt(endflow,26). doAt(a16,28). doAt(a20,29). doAt(a23,30). doAt(a3,31). doAt(endflow,32). doAt(a7,34). doAt(a24,35). doAt(a3,36). doAt(endflow,37). doAt(a4,39). doAt(a8,40). doAt(a3,41). doAt(endflow,42). compAt(a21,x10,5). leftrightnexts(30,34). leftrightnexts(29,39). leftrightnexts(24,28). leftrightnexts(16,20).