n = int(input())
a = [0 for _ in range(n+1)]

if n>=5:
	a[0] = 1
	a[1] = 1
	a[2] = 2
	a[3] = 2
	a[4] = 3
	mod = 10 ** 9 + 7
	for i in range(5, n+1):
		a[i] = (a[i-3] + a[i-2])%mod
	print(a[n])
else:
	a = [1,1,2,2,3]
	print(a[n])