#include <iostream>
#include <queue>
#include <vector>
#include <cmath>
#include <algorithm>
#include <map>
#include <numeric>

using namespace std;
using ll = long long;
const ll INF = 1e9;
const ll MOD = 1e9 + 7;

ll dp[1000010][3];

int main() {
    int N;
    cin >> N;

    dp[0][0] = 1;
    for (int i = 0; i < N; i++) {
        dp[i+1][0] = (dp[i][1] + dp[i][2]) % MOD; // パー
        dp[i+1][1] = dp[i][0] % MOD; // ケン
        dp[i+1][2] = dp[i][1] % MOD; // ケン2回目
    }

    cout << (dp[N][0] + dp[N][1] + dp[N][2]) % MOD << endl;

    return 0;
}