N = int(input())
dp = [[None] * 3 for _ in range(N+1)]
dp[1][0] = 0
dp[1][1] = 1
dp[1][2] = 0

for i in range(1,N):
    dp[i+1][0] = dp[i][1] + dp[i][2]
    dp[i+1][1] = dp[i][0]
    dp[i+1][2] = dp[i][1]

print(sum(dp[N])%(10**9+7))