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(11,19). next(19,20). next(20,21). next(21,22). next(22,23). next(23,24). next(24,25). next(25,26). next(26,27). next(27,28). next(28,29). next(23,30). 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(38,39). next(39,40). next(40,41). doAt(startflow,6). doAt(a7,8). doAt(a3,9). doAt(a13,10). doAt(a2,11). doAt(a16,12). doAt(a24,13). doAt(a10,14). doAt(a14,15). doAt(a11,16). doAt(endflow,17). doAt(a9,19). doAt(a1,20). doAt(a21,21). doAt(a8,22). doAt(a25,23). doAt(a5,24). doAt(a15,25). doAt(a14,26). doAt(a11,27). doAt(endflow,28). doAt(a22,30). doAt(a12,31). doAt(a20,32). doAt(a6,33). doAt(a23,34). doAt(a19,35). doAt(a17,36). doAt(a18,37). doAt(a14,38). doAt(a11,39). doAt(endflow,40). compAt(a7,x23,7). leftrightnexts(24,30). leftrightnexts(12,19).