You are designing a database for a staff management system for an organisation. The organisation has a number of departments. Each department manages a number of projects and has a number of staff members. Each staff member has a name, a unique staff ID$,$ a date of birth, and a contact phone number. Staff work for a department and are assigned to work on projects. Each project has a name which does not have to be unique, and a single staff member who acts as project leader. Multiple staff can work on a single project, and each staff member can be working on any number of projects.