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(13,18). next(18,19). next(19,20). next(20,21). next(21,22). next(22,23). next(23,24). next(20,25). next(25,26). next(26,27). next(27,28). next(28,29). next(12,30). next(30,31). next(31,32). next(32,33). next(33,34). next(34,35). next(31,36). next(36,37). next(37,38). next(38,39). next(30,40). next(40,41). next(41,42). next(42,43). next(43,44). next(44,45). next(45,46). next(46,47). doAt(startflow,4). doAt(a19,6). doAt(a9,8). doAt(a14,9). doAt(a25,10). doAt(a3,11). doAt(a24,12). doAt(a23,13). doAt(a11,14). doAt(a8,15). doAt(endflow,16). doAt(a2,18). doAt(a13,19). doAt(a1,20). doAt(a18,21). doAt(a8,22). doAt(endflow,23). doAt(a12,25). doAt(a4,26). doAt(a8,27). doAt(endflow,28). doAt(a22,30). doAt(a10,31). doAt(a20,32). doAt(a8,33). doAt(endflow,34). doAt(a16,36). doAt(a8,37). doAt(endflow,38). doAt(a5,40). doAt(a17,41). doAt(a21,42). doAt(a7,43). doAt(a15,44). doAt(a8,45). doAt(endflow,46). compAt(a19,x17,5). subsAt(a9,7). leftrightnexts(21,25). leftrightnexts(14,18). leftrightnexts(32,36). leftrightnexts(31,40). leftrightnexts(13,30).