Please develop an E-R diagram to illustrate the following situation: If you need to make assumptions, please state them. Every entity type should have at least two attributes. There is no need to model possible supertype/subtype relationships.

A cleaning company provides custodial services to an office park in suburban Boston. The company employs supervisors and custodians. All of them are identified with an employee ID; the company needs to also keep track of their names and cell phone numbers. Each custodian reports to exactly one supervisor. Each supervisor is responsible for a specific building in the office park; buildings have a number, name, and a specific address. Each building consists of rooms, each of which has a number; there might be special cleaning instructions associated with each room.