N = input()

lis = [0 for i  in range(N + 1)]
lis[1] = 1
odd = 1
even = 0

for i in range(2, N + 1):
    if i % 2 == 0:
        lis[i] = i * odd
        even += lis[i]
    else:
        lis[i] = i * even
        odd += lis[i]

print lis[N]