#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <stdio.h>
#include <cstring>
#include <queue>
#include <stack>
#include <functional>
#include <math.h>
#include <iomanip>
using namespace std;
#define Would
#define you
const int INF = 999999999;
const int MOD = 1e9 + 7;
const double pi = 3.141592653589793238;

long long dp[1000005][5];
int main() {
	long n;
	cin >> n;
	dp[1][1] = 1;
	for (int i = 2; i <= n; ++i) {
		dp[i][0] = (dp[i - 1][1] + dp[i - 1][2]) % MOD;
		dp[i][1] = dp[i - 1][0] % MOD;
		dp[i][2] = dp[i - 1][1] % MOD;
	}
	cout << (dp[n][0] + dp[n][1] + dp[n][2]) % MOD << endl;
}