#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

#define M 1000001
#define MOD 1000000000+7
ll dp[M][3];	//[0]パ。[i]i回目のケン。

int main() {
	ll n;
	cin >> n;
	
	dp[1][0] = 0;
	dp[1][1] = 1;
	dp[1][2] = 0;
	for (int i = 2;i <= n;i++) {
		dp[i][0] = dp[i - 1][1] + dp[i - 1][2];
		dp[i][1] = dp[i - 1][0];
		dp[i][2] = dp[i - 1][1];
		for (int j = 0;j < 3;j++) {
			dp[i][j] %= MOD;
		}
	}
	ll ans = 0;
	for (int i = 0;i < 3;i++) {
		ans += dp[n][i];
		ans %= MOD;
	}
	cout << ans << endl;




	return 0;
}