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(22,23). next(23,24). next(24,25). next(25,26). next(26,27). next(18,28). next(28,29). next(29,30). next(30,31). next(31,32). next(32,33). doAt(startflow,2). doAt(a21,3). doAt(a16,4). doAt(a12,5). doAt(a4,6). doAt(a17,7). doAt(a23,8). doAt(a11,9). doAt(a6,10). doAt(a24,11). doAt(a7,12). doAt(a14,13). doAt(a3,14). doAt(a2,15). doAt(a18,16). doAt(a25,17). doAt(a9,18). doAt(a15,19). doAt(a19,20). doAt(a8,21). doAt(a10,22). doAt(a20,23). doAt(a1,24). doAt(a13,25). doAt(endflow,26). doAt(a22,28). doAt(a20,29). doAt(a1,30). doAt(a13,31). doAt(endflow,32). leftrightnexts(19,28).