Lost on 4th Task of teachers.py

# The dictionary will look something like:
# {'Andrew Chalkley': ['jQuery Basics', 'Node.js Basics'],
#  'Kenneth Love': ['Python Basics', 'Python Collections']}
#
# Each key will be a Teacher and the value will be a list of courses.
#
# Your code goes below here.
def num_teachers(dictionary):
    return len(dictionary)

def num_courses(dictionary):
    total_list = []
    for value in dictionary.values():
        total_list += value
    return len(total_list)

def courses(dictionary):
    single_list = []
    for value in dictionary.values():
        single_list += value
    return single_list

def most_courses(dictionary):
    max_count = 0
    for teacher, course in dictionary.items():
        if len(course) > max_count:
            max_count = len(course)
            name = teacher
        return name