# TODO
a = eval(input())
b = eval(input())
Sum = 0

for i in range(a, b + 1):
    if i % 2 == 0:
        Sum += i

print(Sum)
370f2f723f97c04e968de0064b8580b089f3bd9c
<mask token>

<mask token>
for i in range(a, b + 1):
    if i % 2 == 0:
        Sum += i
print(Sum)

a = eval(input())
b = eval(input())
Sum = 0
for i in range(a, b + 1):
    if i % 2 == 0:
        Sum += i
print(Sum)

# TODO
a = eval(input())
b = eval(input())
Sum = 0

for i in range(a, b + 1):
    if i % 2 == 0:
        Sum += i

print(Sum)