#include <iostream>

using namespace std;

#define MOD 1000000007

long long int dp[3][1000005];

int main() {
	int n;
	cin >> n;
	dp[0][0] = 1;
	dp[1][0] = 0;
	dp[2][0] = 0;
	dp[0][1] = 0;
	dp[1][1] = 1;
	dp[2][1] = 1;
	for (int i = 1; i < n; i++) {
			dp[0][i] = dp[2][i - 1];
			dp[1][i] = dp[0][i - 1];
			dp[2][i] = (dp[0][i - 1] + dp[1][i - 1])%MOD;
	}
	int ans=dp[0][n - 1] + dp[1][n - 1] % MOD + dp[2][n - 1] % MOD;
	ans %= MOD;
	cout << ans << endl;
	return 0;
}