#include "bits/stdc++.h"

using namespace std;

using ll = long long int;
using ld = long double;

using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<double, double>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vd = vector<double>;
using vvd = vector<vd>;
using vs = vector<string>;
using vb = vector<bool>;
using vvb = vector<vb>;

const int INF = (1 << 30) - 1;
const ll INF64 = ((ll)1 << 62) - 1;
const double PI = 3.1415926535897932384626433832795;

const int dx[] = { 0, 1, 0, -1 };
const int dy[] = { -1, 0, 1, 0 };

int gcd(int x, int y) { return y ? gcd(y, x % y) : x; }
ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : x; }
int lcm(int x, int y) { return x / gcd(x, y) * y; }
ll lcm(ll x, ll y) { return x / gcd(x, y) * y; }

const ll MOD = 1000000007;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	int n;
	cin >> n;

	vvl dp(n + 4, vl(4));
	dp[1][1] = dp[2][2] = dp[3][3] = 1;

	for (int i = 1; i < n; i++) {
		dp[i + 1][1] = (dp[i + 1][1] + (dp[i][2] + dp[i][3]) % MOD) % MOD;
		dp[i + 2][2] = (dp[i + 2][2] + (dp[i][1] + dp[i][3]) % MOD) % MOD;
		dp[i + 3][3] = (dp[i + 3][3] + (dp[i][1] + dp[i][2]) % MOD) % MOD;
	}
	
	ll res = (dp[n][1] + (dp[n][2] + dp[n][3]) % MOD) % MOD;
	cout << res << endl;
	return 0;
}