#include <iostream>
using namespace std;

int main(){
	int n;
	cin >> n;
	int64_t dp[n + 1][4]{};
	dp[1][1] = dp[2][2] = 1;
	if(1 < n) dp[3][3] = 1;
	for(int i = 3; i <= n; i++) for(int j = 1; j <= 3; j++) (dp[i][j] += dp[i - j][1] + dp[i - j][2] + dp[i - j][3] - dp[i - j][j]) %= int64_t(1e9 + 7);
	cout << (dp[n][1] + dp[n][2] + dp[n][3]) % int64_t(1e9 + 7) << endl;
}