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(19,20). next(20,21). next(21,22). next(14,23). next(23,24). next(24,25). next(25,26). next(26,27). next(27,28). next(28,29). next(29,30). next(30,31). doAt(startflow,6). doAt(a3,7). doAt(a6,10). doAt(a15,11). doAt(a11,13). doAt(a13,14). doAt(a1,15). doAt(a2,16). doAt(a14,17). doAt(a8,18). doAt(a9,19). doAt(a4,20). doAt(endflow,21). doAt(a7,23). doAt(a10,24). doAt(a5,25). doAt(a14,26). doAt(a8,27). doAt(a9,28). doAt(a4,29). doAt(endflow,30). compAt(a11,x9,8). compAt(a6,x9,9). compAt(a11,x9,12). leftrightnexts(15,23).