N = int(input())

if N == 1:
	print(1)
else:
	KP = [[0, 0] for i in range(N)]
	KP[0][0] = 1
	KP[1][0] = 1
	KP[1][1] = 1
	for i in range(2, N):
		KP[i][0] = (KP[i - 2][1] + KP[i - 1][1]) % 1000000007
		KP[i][1] = KP[i - 1][0] % 1000000007

	print(sum(KP[N - 1]) % 1000000007)