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

int main() {
    ll n;
    cin >> n;
    if (n > 2) {
        // 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;
    } else {
        cout<<n<<endl;
    }

    system("pause");
}