#include<iostream>
#include<string>
#include<string.h>
#include<algorithm>
#include<stdio.h>
#include<cmath>
#include<vector>
#include<utility>
#include<stack>
#include<queue>
#include<list>
#include<bitset>

#define FOR(i, a, b) for(int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000

using namespace std;
long long int dp[3][1000001] = {};

int main(void) {
	
	int n;
	long long int total = 0;

	cin >> n;

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


	FOR(i, 2, n) {
		dp[0][i] = dp[1][i - 1] + dp[2][i - 1];
		dp[1][i] = dp[0][i - 1];
		dp[2][i] = dp[1][i - 1];
		if (dp[0][i] > MOD) {
			dp[0][i] %= MOD;
		}
		if (dp[1][i] > MOD) {
			dp[1][i] %= MOD;
		}
		if (dp[2][i] > MOD) {
			dp[2][i] %= MOD;
		}
	}
	total = dp[0][n] + dp[1][n] + dp[2][n];
	if (total > MOD) {
		total %= MOD;
	}
	cout << total << endl;
	return 0;
}