The files containing the MM-CEARP 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 {<a11>,<a12>,...,<a1m>}