#include<bits/stdc++.h>
#define EM 1000000
using namespace std;
using LL = long long;
using P = pair<LL, LL>;
LL LINF = 1e18;
int INF = 1e9;
LL mod = 1e9+7;
using vint = vector<int>;
using vLL = vector<LL>;
using vvint = vector<vector<int>>;
using vvLL = vector<vector<LL>>;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

int main(){
    int N;
    cin >> N;
    vector<LL> ken1(N+1, 0), ken2(N+1, 0), pa(N+1, 0);
    ken1[1] = 1;
    for(int i = 2;i <= N;i++) {
        ken1[i] = pa[i - 1];
        ken2[i] = ken1[i - 1];
        pa[i] = (ken1[i - 1] + ken2[i - 1])%mod;
    }
    LL ans = (ken1[N] + ken2[N] + pa[N])%mod;
    cout << ans << endl;
}