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(12,17). next(17,18). next(18,19). next(19,20). next(20,21). next(21,22). next(19,23). next(23,24). next(24,25). next(25,26). next(26,27). next(27,28). next(28,29). next(29,30). next(30,31). next(28,32). next(32,33). next(33,34). next(34,35). next(35,36). next(36,37). next(34,38). next(38,39). next(39,40). next(32,41). next(41,42). next(42,43). next(43,44). next(44,45). next(42,46). next(46,47). next(47,48). doAt(startflow,4). doAt(a17,8). doAt(a21,9). doAt(a10,10). doAt(a3,11). doAt(a24,12). doAt(a11,13). doAt(a14,14). doAt(endflow,15). doAt(a23,17). doAt(a13,18). doAt(a1,19). doAt(a19,20). doAt(endflow,21). doAt(a4,23). doAt(a15,24). doAt(a12,25). doAt(a18,26). doAt(a2,27). doAt(a5,28). doAt(a8,29). doAt(endflow,30). doAt(a25,32). doAt(a16,33). doAt(a6,34). doAt(a22,35). doAt(endflow,36). doAt(a20,38). doAt(endflow,39). doAt(a7,41). doAt(a6,42). doAt(a22,43). doAt(endflow,44). doAt(a20,46). doAt(endflow,47). compAt(a21,x2,5). compAt(a17,x2,6). subsAt(a17,7). leftrightnexts(35,38). leftrightnexts(43,46). leftrightnexts(33,41). leftrightnexts(29,32). leftrightnexts(20,23). leftrightnexts(13,17).