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(17,21). next(21,22). next(22,23). next(16,24). 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(28,34). next(34,35). next(35,36). next(36,37). next(37,38). next(38,39). next(39,40). doAt(startflow,3). doAt(a3,5). doAt(a8,6). doAt(a10,7). doAt(a16,8). doAt(a23,9). doAt(a24,10). doAt(a21,11). doAt(endflow,12). doAt(a9,14). doAt(a13,15). doAt(a14,16). doAt(a11,17). doAt(a5,18). doAt(endflow,19). doAt(a12,21). doAt(endflow,22). doAt(a4,24). doAt(a25,25). doAt(a18,26). doAt(a15,27). doAt(a7,28). doAt(a19,29). doAt(a17,30). doAt(a20,31). doAt(endflow,32). doAt(a22,34). doAt(a1,35). doAt(a2,36). doAt(a17,37). doAt(a20,38). doAt(endflow,39). compAt(a3,x16,4). leftrightnexts(18,21). leftrightnexts(29,34). leftrightnexts(17,24). leftrightnexts(11,14).