My code get exactly output, but couldn't pass the quiz

# 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_teacher):
    return len(dict_teacher.keys())

def num_courses(dict_teacher):
    length = []
    for value in dict_teacher.values():
        length.extend(value)
    return len(length)

def courses(dict_teacher):
    length = []
    for value in dict_teacher.values():
        length.extend(value)
    return length

def most_courses (dict_teacher):
    mos_tea = ""
    max_courses = 0
    for teacher in dict_teacher.keys():
        if len(dict_teacher[teacher]) > max_courses:
            max_couses = len(dict_teacher[teacher])
            mos_tea = teacher
    return mos_tea

    def stats (dict_teacher):
    lists=[]
    for teacher in dict_teacher:
        ini_list = [teacher,len(dict_teacher[teacher])]
        lists.append(ini_list)
    return lists