need help

# 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(dict):
    return len(dict.keys())

def num_courses(dict):
    counter = 0
    for key in dict:
        amount = len(dict[key])
        counter += amount
    return counter 

def courses(dict):
    course_list = []
    for key in dict:
        course_list.extend(dict[key])
    return course_list


def most_courses(dict):
    highest_number = 0
    teacher = ''
    for key in dict:
        if Len(dict[key]) > highest_number:
            teacher = key
    return teacher