/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author
 */

#include <iostream>
#include <fstream>

#include <iostream>
#include "bits/stdc++.h"

using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef int                     integer;
#define int                     long long
typedef pair<int, int>          pii;
#define vii                     vector<pair<int,int>>
#define vi                      vector<int>
#define vvi                     vector<vector<int>>
#define rep(i, a, b)            for(int i = a; i < (b); i++)
#define s(x)                    in>>x
#define s2(x,y)                 in>>x>>y
#define s3(x,y,z)               in>>x>>y>>z
#define s4(x,y,z,w)             in>>x>>y>>z>>w
#define p(x)                    out<<(x)<<endl
#define p2(x,y)                 out<<(x)<<' '<<(y)<<endl
#define p3(x,y,z)               out<<(x)<<' '<<(y)<<' '<<(z)<<endl
#define p4(x,y,z,w)             out<<(x)<<' '<<(y)<<' '<<(z)<<' '<<(w)<<endl
#define p1d(a,n)                for(int ix=0;ix<n-1;ix++) out<<a[ix]<<' '; out<<a[n-1]<<'\n';
#define p2d(a,n,m)              for(int ix=0;ix<n;ix++){ for(int jx=0;jx<m;jx++) out<<a[ix][jx]<<" "; out<<endl;}
#define pl(x)                   out<<(x)
#define pll(x)                  out<<(x)<<' '
#define range(v)                v.begin(),v.end()
#define all(x)                  begin(x), end(x)
#define sz(x)                   (int)(x).size()
#define rst(x)                  memset(x, -1, sizeof(x))
#define UNVISITED               -1
#define VISITED                 0
#define EXPLORED                2

#define EACH(x, a) for (auto& x: a)
template<class T> void read_v(T& x, std::istream& in) {
    in >> (x);
}
template<class A> void read_vec(vector<A>& x, std::istream& in) {
    EACH(a, x)
        read_v(a, in);
}

bool sortpairbysec(const pair<int,int> &a,const pair<int,int> &b){return (a.second < b.second);}
template <typename T>
T factmod(T a, T modulus){ int res = 1, i; for (i = 2; i <= a; i++){ res *= i; res%=modulus;} return res; }
template <typename T>
int powmod(T a,T b, const int m){ int ans=1; while(b>0){if(b&1){ans*=a;ans%=m;}a*=a;a%=m;b>>=1;} return ans; }
template <typename T>
int power(T a, T b){ int ans=1; while(b>0){if(b&1){ans*=a;}a*=a;b>>=1;}return ans;}

const int MAXN=2005;
const int CMOD=1e9+7;
int factor[MAXN];
void cal_factor(){factor[0]=1;for(int u=1;u<MAXN;u++){factor[u]=(factor[u-1]*u)%CMOD;}}
ll CombMOD(ll n,ll k){return factor[n]*powmod(factor[n-k], CMOD-2, CMOD)%CMOD*powmod(factor[k],CMOD-2, CMOD)%CMOD;}


void ssolve(std::istream& in, std::ostream& out){
    int n; s(n);
    cal_factor();
    int ans = 0;
    for(int terms = 1; terms <= (n/3); terms++){
        int r = (n - terms * 3);
        ans += CombMOD(terms + r - 1, r);
        ans %= CMOD;
    }
    p(ans);
    return;
}

class DRedistribution {
public:
void solve(std::istream& in, std::ostream& out) {
    ios_base::sync_with_stdio(false);
    in.tie(nullptr);out.tie(nullptr);
    int t;
    int READ = 0;
    if(READ) s(t);
    else t = 1;
    while(t--){
        ssolve(in, out);
    }
}
};

integer main() {
    DRedistribution solver;
    std::istream& in(std::cin);
     std::ostream& out(std::cout);
     solver.solve(in, out);
}

Measured memory_bytes: 3608