#include <iostream>
using namespace std;

/* dp[i][j]  j = 0 : ケン　j = 1 : ケンケン　j = 2 : パ*/
long long dp[1000000][3];
long long mod = 1000000007;

int main() {
	cin.tie(0); ios::sync_with_stdio(false);
	int N; cin >> N;
	dp[1][0] = 1; dp[1][1] = 0; dp[1][2] = 0;
	for (int i = 2; i <= N; i++) {
		dp[i][0] = dp[i - 1][2];
		dp[i][1] = dp[i - 1][0];
		dp[i][2] = (dp[i - 1][0] + dp[i - 1][1])%mod;
	}
	cout << (dp[N][0] + dp[N][1] + dp[N][2]) % mod << endl;
	return 0;
}