# define lists for all required data
student_names = []
test_1_marks = []
test_2_marks = []
test_3_marks = []
total_marks = []
# define number of students to record data for
number_of_students = 30
# define variable for storing total marks gained by all students overall
sum = 0

# function for prompting user for input, then checking it against conditions
def getMark(test_number, student_index, max_mark):
    # keep asking for the mark until a valid mark is entered
    mark = None
    while not mark:
        # ask for mark of given student, for given test number
        mark = input("%s test %d mark: " % (student_names[student_index], test_number))
        # check if mark is given and that it's numeric
        if (mark and mark.isnumeric()):
            # check mark is in acceptable range of values
            if (int(mark) < 0 or int(mark) > max_mark):
                mark = None
        else:
            mark = None
        # if input is invalid, print error message
        if not mark:
            print("Invalid input. Please enter a number between 0 and %d." % max_mark)
    # return mark
    return int(mark)

# do this for all students
for i in range(number_of_students):
    # retrieve and store student's name
    student_names.append(input("Student %d name: " % (i + 1)))

# do this for all students
for i in range(number_of_students):
    # retrieve and store student's test marks
    # test #1 has a max mark of 20
    test_1_marks.append(getMark(1, i, 20))
    # test #2 has a max mark of 25
    test_2_marks.append(getMark(2, i, 25))
    # test #3 has a max mark of 35
    test_3_marks.append(getMark(3, i, 35))
    # record student's total marks
    total_marks.append(test_1_marks[i] + test_2_marks[i] + test_3_marks[i])
    # add student's total marks to sum of all marks gained by all students overall
    sum += total_marks[-1]

# print each student's total marks
for i in range(number_of_students):
    print("%s: %d" % (student_names[i], total_marks[i]))

# print average total for all students
print("Average total: %.2f" % (sum / 30))