ABC Company has four locations total, all connected via an IP WAN. Each location has a Cisco Unified Communications Manager cluster and the headquarters cluster is connected to all other clusters via intercluster trunks. ABC wants to allow up to eight simultaneous calls across the IIP WAN. To call between sites, an employee dials a 2-digit access code plus a 4-digit extension. If more than eight calls are made, or if the IP WAN is not available. Calls should be sent to ABC Company's preferred long-distance carrier. If the trunk to the long-distance carrier is not available, the local provider should be used. The long-distance carrier requires 10 digits to complete a long distance call. The local provider requires 11 digits to complete a long-distance call but only 7 digits local calls. What is the minimum number of route lists required at the headquarters locations?