#include "bits/stdc++.h"
using namespace std;
typedef long long ll;

template <typename T>
void print_vec(const vector<T>& v, bool is_reverse=false, int num=0){
  if(num == 0) num = (int)v.size();
  if(is_reverse) for(int i=num-1; i>=0; i--){ cout<<v[i]; if(i!=0) cout<<" ";}
  else for(int i=0; i<num; i++){ cout<<v[i]; if(i!=num-1) cout<<" ";}
  cout << endl;
}

template <typename T>
void print_pairvec(const vector<T> &v, int num=0){
  if(num == 0) num = (int)v.size();
  cout << endl;
  for(int i=0; i<num; i++){ cout << v[i].first << " " << v[i].second << endl;}
}


template <typename TYPE>
void print_vec2(const vector<vector<TYPE>>& v){
  cout << endl; cout << "       ";
  for(int i=0; i<v[0].size(); i++) cout << i << "   "; 
  cout << endl;
	for(int i=0; i<v.size(); i++){
		cout << "i=" << i << ":   ";
		for(int j=0; j<v[i].size(); j++){
			if(v[i][j] == 0) cout << "\x1B[0m" << v[i][j] << "   ";
      else cout << "\x1B[31m" << v[i][j] << "   ";//https://stackoverrun.com/ja/q/12618775
		}
		cout << "\x1B[0m" << endl;
	}
}

// auto mod int
// https://youtu.be/L8grWxBlIZ4?t=9858
// https://youtu.be/ERZuLAxZffQ?t=4807 : optimize
// https://youtu.be/8uowVvQ_-Mo?t=1329 : division
const int mod = 1000000007;
// const int mod = 998244353;
struct mint {
  ll x; // typedef long long ll;
  mint(ll x=0):x((x%mod+mod)%mod){}
  mint operator-() const { return mint(-x);}
  mint& operator+=(const mint a) {
    if ((x += a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator-=(const mint a) {
    if ((x += mod-a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;}
  mint operator+(const mint a) const { return mint(*this) += a;}
  mint operator-(const mint a) const { return mint(*this) -= a;}
  mint operator*(const mint a) const { return mint(*this) *= a;}
  mint pow(ll t) const {
    if (!t) return 1;
    mint a = pow(t>>1);
    a *= a;
    if (t&1) a *= *this;
    return a;
  }

  // for prime mod
  mint inv() const { return pow(mod-2);}
  mint& operator/=(const mint a) { return *this *= a.inv();}
  mint operator/(const mint a) const { return mint(*this) /= a;}
};
istream& operator>>(istream& is, mint& a) { return is >> a.x;}
ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}


// combination mod prime
// https://www.youtube.com/watch?v=8uowVvQ_-Mo&feature=youtu.be&t=1619
struct combination {
  vector<mint> fact, ifact;
  combination(int n):fact(n+1),ifact(n+1) {
    assert(n < mod);
    fact[0] = 1;
    for (int i = 1; i <= n; ++i) fact[i] = fact[i-1]*i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i) ifact[i-1] = ifact[i]*i;
  }
  mint operator()(int n, int k) {
    if (k < 0 || k > n) return 0;
    return fact[n]*ifact[k]*ifact[n-k];
  }
};

int main(){
  int S;
  cin >> S;

  const int DIGIT = 667;
  const int MAX = 2000;
  combination comb(MAX+5);

  mint ans = 0;
  for(int i=0; i<=DIGIT; i++){
    int tmp = S - 3*(i+1);
    // cout << " i: " << i << " tmp: " << tmp << " comb(tmp, i): " << comb(tmp, i) << endl;
    ans += comb(tmp+i, i);
  }
  cout << ans << endl;


  // TLE解答
  // const int DIGIT = 667;
  // const int MAX = 2000;
  // vector<vector<mint>> dp(DIGIT+5, vector<mint>(MAX+5, 0));
  // dp[0][0] = 1;
  // for(int i=0; i<=DIGIT; i++){
  //   for(int j=0; j<=MAX; j++){
  //     for(int num=3; num<=MAX; num++){
  //       if(num+j <= MAX) dp[i+1][j+num] += dp[i][j];
  //     }
  //   }
  // }
  

  // mint ans = 0;
  // for(int i=0; i<=DIGIT; i++) ans += dp[i][S];
  // cout << ans << endl;
	return 0;
}



Measured memory_bytes: 3680