#include "bits/stdc++.h"
using namespace std;

int main() {
	int N, MOD = 1000000007;
	static long long DP[1000010][3] = {};
	DP[0][1] = 1;
	cin >> N;
	for (int i = 1; i <= N; i++) {
		DP[i][0] = DP[i - 1][2];
		DP[i][0] %= MOD;
		DP[i][1] = DP[i - 1][0] + DP[i - 1][2];
		DP[i][1] %= MOD;
		DP[i][2] = DP[i - 1][1];
		DP[i][2] %= MOD;
	}
	cout << (DP[N][0] + DP[N][1] + DP[N][2]) % MOD << endl;
}