N = int(input())

maxf = N  # <-- input factional limitation
mod = int(1e9) + 7
def doubling(n, m):
    y = 1
    base = n
    tmp = m
    while tmp != 0:
        if tmp % 2 == 1:
            y *= base
            y %= mod
        base *= base
        base %= mod
        tmp //= 2
    return y

def inved(a):
    x, y, u, v, k, l = 1, 0, 0, 1, a, mod
    while l != 0:
        x, y, u, v = u, v, x - u * (k // l), y - v * (k // l)
        k, l = l, k % l
    return x % mod
    
prod = 1
S = 0
for i in range(N // 2 + 1):
    S += prod
    prod *= (N - 2 * i - 1) * (N - 2 * i)
    prod //= (N - i) * (i + 1)
print(S)