#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;

#define rep(i, r) for(int i = 0; i < (r); ++i)
#define reps(i, s, r) for(int i = (s); i < (r); ++i)
#define fore(i, m2) for(auto &i : m2)
#define vi vector<int>
#define vl vector<ll>
#define pl pair<ll, ll>
#define all(i) (i).begin(), (i).end()
#define fs first
#define sc second

template <class T> bool chmin(T &i, T b) {
    if(i > b) {
        i = b;
        return true;
    }
    return false;
}
template <class T> bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}

const ll INF = LONG_LONG_MAX / 3;
const ll MOD = 1'000'000'007;
const ll MAX = 1e6 + 5;



int main() {

    ll n;
    cin >> n;
    ll a = 1, b = 0, c = 0, ta, tb, tc;

    while(n--) {
        ta = a, tb = b, tc = c;
        a = (tb + tc) % MOD;
        b = ta;
        c = tb;
    }

    cout << ((a + b) % MOD + c) % MOD << endl;
}