k = int(eval(input()))

count = 0

for i in range(k):

    for j in range(i+1, k):

        if (i % 2 == 0 and j % 2 == 1) or (i % 2 == 1 and j % 2 == 0):

            count +=1

print(count)
k = int(eval(input()))

print(((k // 2) * (k - k // 2)))

k = int(eval(input()))
count = 0
for i in range(k):
    for j in range(i + 1, k):
        if (i % 2 == 0 and j % 2 == 1) or (i % 2 == 1 and j % 2 == 0):
            count += 1
print(count)

k = int(eval(input()))
print(((k // 2) * (k - k // 2)))

-count = 0 -for i in range(k): -    for j in range(i + 1, k): -        if (i % 2 == 0 and j % 2 == 1) or (i % 2 == 1 and j % 2 == 0): -            count += 1 -print(count) +print(((k // 2) * (k - k // 2)))