#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
int n, dp[1000009][4];
int main() {
	cin >> n; dp[0][0] = 1;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= i && j <= 3; j++) {
			for(int k = 0; k <= 3; k++) {
				if(j != k) {
					dp[i][j] += dp[i - j][k];
					if(dp[i][j] >= mod) dp[i][j] -= mod;
				}
			}
		}
	}
	cout << (1LL * dp[n][1] + dp[n][2] + dp[n][3]) % mod << endl;
	return 0;
}