p = 10**9+7
N = input()
dp = [[0]*3 for i in xrange(N)]
dp[0][1] = 1
for i in xrange(N-1):
	for j in xrange(2):
		dp[i+1][j+1] += dp[i][j]
		dp[i+1][0] += dp[i][j+1]
		dp[i+1][j+1] %= p
		dp[i+1][0] %= p
print sum(dp[N-1]) % p