// コピーして使う！
#include <bits/stdc++.h>
using namespace std;
using ll = int64_t;

int main() {
    ll n;
    cin >> n;
    // vector[n][i] iがケンケンパに対応(0,1,2)
    vector<vector<ll>> dp(n + 1, vector<ll>(3));
    ll ans = 0, mod = pow(10, 9) + 7;
    dp[1][0] = 1;
    dp[1][1] = 0;
    dp[1][2] = 0;
    dp[2][0] = 0;
    dp[2][1] = 1;
    dp[2][2] = 1;
    for (ll i = 3; i != dp.size(); 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;
    }
    for (ll i = 0; i != 3; i++) {
        ans = (ans + dp[dp.size() - 1][i]) % mod;
    }
    cout << ans << endl;

    // system("pause");
}