The files containing the PWRPP instances have the following format:

NOMBRE: <name of the instance>
VERTICES: <number of vertices>
ARISTAS: <number of edges>

(<u1>,<u2>) coste <c1> <c2> profit <p>
.
.
.



For each edge between vertices u1 and u2 there is a line 

	(<u1>,<u2>) coste <c1> <c2> profit <p>

where c1 is the cost of traversing the edge from u1 to u2, 
c2 is the cost of traversing it from u2 to u1, 
and p is the profit obtained in any direction.