M, N = 10 ** 9 + 7, 10 ** 6


def main():
    n = int(input())

    dp = [0 for i in range(N+1)]
    dp[0], dp[2] = 1, 1
    for i in range(3, n+1):
        dp[i] = dp[i-2] + dp[i-3]
        if dp[i] >= M:
            dp[i] %= M

    ans = dp[n] + dp[n-1]
    if n > 1:
        ans += dp[n-2]
    print(ans%M)


if __name__ == '__main__':
    main()