import math
N = int(input())
count = 0
cn = 1
for n2 in range(N//2+1):
    n3 = (N-2*n2)//3
    cn = math.factorial(n2+n3) // (math.factorial(n2) * math.factorial(n3))
    count += cn%(10**9+7)
print(count%(10**9+7))