Task 4 of teachers.py no longer passing after editing code for task 5?

# 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(dic):
    return len(dic)

def num_courses(dic):
    total = 0
    for i in dic:
        total += len(dic[i])
    return total

def courses(dic):
    thing = []
    for value in dic.values():
        thing += value
    return thing

def most_courses(dic):
    max_count = 0
    teacher_most_classes = " "
    for key in dic:
        if len(dic[key]) > max_count:
            max_count = len(dic[key])
            teacher_most_classes = key
    return key

def stats(dic):
    outer_list = []
    for key in dic:
        inner_list = []
        inner_list.append(key)
        inner_list.append(len(dic[key]))
        outer_list.append(inner_list)
    return outer_list