n = int(input())

def mod(i):
	return i % (10**9 + 7)

dp = [[0 for _ in range(3)] for _ in range(n)]
dp[0][0] = 0
dp[0][1] = 1
dp[0][2] = 0

for i in range(n-1):
	dp[i+1][0] = mod(dp[i][1] + dp[i][2])
	dp[i+1][1] = dp[i][0]
	dp[i+1][2] = dp[i][1]
	
print(mod(sum(dp[-1])))