number_list = []
for i in range(1, 46):
    number_list += [i] * i
A, B = map(int, input().split())
print(sum(number_list[A - 1:B]))

eda2cbd3a6711df6462952f4361c32651499800a
<mask token>

<mask token>
for i in range(1, 46):
    number_list += [i] * i
<mask token>
print(sum(number_list[A - 1:B]))

number_list = []
for i in range(1, 46):
    number_list += [i] * i
A, B = map(int, input().split())
print(sum(number_list[A - 1:B]))
