using System;
using System.Collections.Generic;
using System.Linq;

class Magatro
{
    static void Main()
    {
        int mod = 1000000007;
        int N = int.Parse(Console.ReadLine());
        int[] dp = new int[1000001];
        dp[1] = 1;
        dp[2] = 2;
        dp[3] = 2;
        for(int i = 4; i <= 1000000; i++)
        {
            dp[i] = (dp[i - 2] + dp[i - 3]) % mod;

        }
        Console.WriteLine(dp[N]);
    }
}