The files containing the UR instances have the following format:

NOMBRE: <name of the instance>
COMENTARIO: <comment>
VERTICES: <number of vertices>
CLIENTES: <number of customers>
ARCOS_REQ: <number of required arcs>
ARCOS_NOREQ: <number of non-required arcs>
LIST OF REQUIRED ARCS:
(<u1>,<u2>) coste <c>
.
.
.
LIST OF NO REQUIRED ARCS:
(<u1>,<u2>) coste <c> 
.
.
.
CONJUNTOS H :
{<a11>,<a12>,...,<a1m>}
.
.
.


Entries <name of instance> and <comment> may be empty.
For each required arc from node u1 to node u2 there is a line 

	(<u1>,<u2>) coste <c>

where c is the cost of traversing the arc. 

For each non-required arc from node u1 to node u2 there is a line 

	(<u1>,<u2>) coste <c> 

where c is the cost of traversing the arc.

The list of customers is given after "CONJUNTOS H :". 
Each line contains, in braces, the list of arcs from which each customer is serviced