#include <iostream>
#include <cstdio>
#include <vector>

using namespace std;

const int mod = 1e9 + 7;

int main() {
	int n;
	cin >> n;

	vector<vector<long long>> a(4, vector<long long>(n + 10, 0));
	a[1][1] = 1;
	a[2][2] = 1;
	a[3][3] = 1;

	for (int i = 1; i < n; i++) {
		for (int j = 1; j <= 3; j++) {
			if (a[j][i] == 0) {
				continue;
			}

			for (int k = 1; k <= 3; k++) {
				if (k == j) {
					continue;
				}
				a[k][i+k] += a[j][i];
				a[k][i+k] %= mod;
			}

		}
	}

	int ans = (a[0][n] + a[1][n] + a[2][n] + a[3][n]) % mod;
	cout << ans << endl;
	return 0;
}