#define _USE_MATH_DEFINES
#include<iostream>
#include <math.h>
#include <climits>
#include <algorithm>
#include <vector>
#include <queue>
#include <string>
using namespace std;

/* sample input

*/
long long n;
long long dp[1000001][3];

int main()
{
	cin >> n;

	long long a = 1000000000 + 7;

	dp[1][0] = 1;
	dp[1][1] = 0;
	dp[1][2] = 0;
	dp[2][0] = 0;
	dp[2][1] = 1;
	dp[2][2] = 0;
	dp[3][0] = 1;
	dp[3][1] = 1;
	dp[3][2] = 1;

	for (int i = 4; i <= n; i++){
		dp[i][0] = dp[i - 1][1] + dp[i - 1][2]%a;
		dp[i][1] = dp[i - 2][0] + dp[i - 2][2]%a;
		dp[i][2] = dp[i - 3][0] + dp[i - 3][1]%a;
	}
	
	long long answer = (dp[n][0] + dp[n][1] + dp[n][2]) % a;

	cout << answer << endl;
	return 0;
}