question='''
Choose:
1. Add name to committee.
2. Delete name from committee.
3. Is name in committee?
0. Quit

Choice: '''

def MakeCommittee():
    comm=[]
    while True:
        choice=raw_input(question)
        print 
        if choice in '123':
            name=raw_input('name of person: ')
            print
            name=name.strip()  # remove any leading and trailing spaces
            if name=='':
                print 'Error: no name to process'
            else:
                if choice=='1':
                    if name in comm:
                        print '%s is already on the committee' % (name)
                    else:
                        comm.append(name)
                        print '%s added.' % (name)
                elif choice=='2':
                    if name in comm:
                        comm.remove(name)
                        print '%s removed.' % (name)
                    else:
                        print 'Error: %s is not on the committee' % (name)
                else:
                    if name in comm:
                        print 'Yes, %s is on the committee' % (name)
                    else:
                        print 'No, %s is not on the committee' % (name)
        elif choice=='0':
            break
        else:
            print 'Error: %s is not a valid choice.' % (choice)
    print 'Done'
    return comm

print MakeCommittee()