@,@,,,@@,,                                          @,@,,,,,@@
@@@,,@,@,@                                          @@@,,,,@,,
,,@,@@@@@@                                          ,,@,,,@@,@
,@@@,,,,,,                                          ,@@,,@,@@@
@,,@,,,,,,                                          @,@,@@@,,@
@,@@,,,,,,                   rails                  @@@@,,@,@,
@@,@,,,,,@                                          ,,,@,@@@@@
,@@@,,,,@,                                          ,,@@@,,,,,
@,,@,,,@@, @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ,@,,@,,,,,
@,@@,,@,@@                                          @@,@@,,,,@
@@,@,@@@,, @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ,@@,@,,,@,
,@@@@,,@,,                                          @,@@@,,@@@
@,,,@,@@,,                                          @@,,@,@,,@
@,,@@@,@,@ trains  are  so  constructed  that  they ,@,@@@@,@,
@,@,,@@@@, have to follow a set path.  this path is @@@,,,@@@@
@@@,@,,,@, called a "railway",  which is  comprised ,,@,,@,,,,
,,@@@,,@@, of two metal rails, hence its  nickname. ,@@,@@,,,@
,@,,@,@,@,                                          @,@@,@,,@@
@@,@@@@@@, because  the  low friction  between  the @@,@@@,@,@
,@@,,,,,@@ wheels of the train and  the rail metal, ,@@,,@@@@,
@,@,,,,@,@ there are limits  for how acute  a curve @,@,@,,,@,
@@@,,,@@@@ can  be,  and even more  so for how much @@@@@,,@@@
,,@,,@,,,@ the  ground   under  the  rails  can  be ,,,,@,@,,,
,@@,@@,,@, sloped.  thus a railway is often not led ,,,@@@@,,,
@,@@,@,@@@ on top of hills, rather  through them in ,,@,,,@,,,
@@,@@@@,,, tunnels   (if   they  are   large),   or ,@@,,@@,,@
,@@,,,@,,@            artificial chasms.            @,@,@,@,@,
@,@,,@@,@@                                          @@@@@@@@@,
@@@,@,@@,@ there will be trees on the  side  of the ,,,,,,,,@@
,,@@@@,@@@ rails, but  not too close, or  they will ,,,,,,,@,,
,@,,,@@,,, be cut  down  by  the  railway janitors. ,,,,,,@@,,
@@,,@,@,,@ there  will be  plains,  and  bodies  of ,,,,,@,@,,
,@,@@@@,@,                  water.                  ,,,,@@@@,@
@@@,,,@@@,                                          ,,,@,,,@@@
,,@,,@,,@, trains  go  by day  and by  night. along ,,@@,,@,,,
,@@,@@,@@@      the way, there is information       ,@,@,@@,,,
@,@@,@@,,@ scattered,  often  put on  top of poles, @@@@@,@,,,
@@,@@,@,@@ to  be interpreted by the train drivers. ,,,,@@@,,@
,@@,@@@@,, different  parts  of  the  railway  have ,,,@,,@,@,
@,@@,,,@,,          different speed limits.         ,,@@,@@@@,
@@,@,,@@,@                                          ,@,@@,,,@@
,@@@,@,@@, sometimes,  trains have to stop and wait @@@,@,,@,,
@,,@@@@,@@ for something to happen, far away.  this ,,@@@,@@,,
@,@,,,@@,@ is  signaled  by  red or  green  lights. ,@,,@@,@,@
@@@,,@,@@,                                          @@,@,@@@@,
,,@,@@@,@@                 @@@@@@@@                 ,@@@@,,,@@
,@@@,,@@,@                                          @,,,@,,@,@
@,,@,@,@@@ many people  follow the rails  by  foot. @,,@@,@@@@
@,@@@@@,,, often this  proves  to  be  the  shorter @,@,@@,,,,
@@,,,,@,,@ path  between two  points. however  this @@@@,@,,,@
,@,,,@@,@@ is  frowned   upon,  and  very  impolite ,,,@@@,,@,
@@,,@,@@,@         toward the train drivers!        ,,@,,@,@@,
,@,@@@,@@@                                          ,@@,@@@,@@
@@@,,@@,,,                                          @,@@,,@@,@
,,@,@,@,,@                                          @@,@,@,@@,
,@@@@@@,@,                                          ,@@@@@@,@,
@,,,,,@@@,                                          @,,,,,@@@,
@,,,,@,,@@                                          @,,,,@,,@@