Input:mobie_users: [{user_id: 1, email: 'user1@example.com', city: 'New York', signup_time: '2022-01-01'}, {user_id: 2, email: 'user2@example.com', city: 'Los Angeles', signup_time: '2022-01-15'}], dail_service_consumption: [{user_id: 1, connection_id: 1, internet_usage: 100, call_minutes: 10, sms_usage: 5}, {user_id: 1, connection_id: 2, internet_usage: 200, call_minutes: 20, sms_usage: 10}, {user_id: 2, connection_id: 1, internet_usage: 300, call_minutes: 30, sms_usage: 15}], network_zones: [{zone_id: 1, zone_type: 'A', generation: '4G', signal_location: 'New York'}, {zone_id: 2, zone_type: 'B', generation: '5G', signal_location: 'Los Angeles'}]
Output:[1, 2]