import pickle

list_students_1 = ['Ogarkov', 'Butko', 'Efimova', 'Antonov']
list_marks_1 = [4.9, 4.3, 4.2, 5.0]

dictionary_2 = input('Введите имя словаря: ').strip()
dictionary_2 = dict(zip(list_students_1, list_marks_1))
print(dictionary_2)


fp_4 = open('zapis.ob', 'wb')
pickle.dump(dictionary_2, fp_4)
fp_4.close()

list_5 = list(dictionary_2.values())
srednee_mark = sum(list_5)/len(list_5)
print(round(srednee_mark, 1))