#include<iostream>
using namespace std;
int main(){
	int n;
	cin >> n;
	static long long int c[1000000][3];
	c[0][0] = 1; c[0][1] = 0; c[0][2] = 0;
	c[1][0] = 0; c[1][1] = 1; c[1][2] = 0;
	for (int i = 1; i <= n; i++){
		c[i][0] = (c[i - 1][1] + c[i - 1][2]) % 1000000007;
		c[i][1] = c[i - 1][0] % 1000000007;
		c[i][2] = c[i - 1][1] % 1000000007;
	}
	cout << (c[n][0] + c[n][1] + c[n][2]) % 1000000007 << endl;
	return 0;
}