#include <iostream>
#include <vector>

using namespace std;

#ifdef __DEBUG__
    void debug_out() { cerr << endl; } 
    template <typename Head, typename... Tail>
    void debug_out(Head H, Tail... T) {cerr << " " << H; debug_out(T...);}
    #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
    #define debug(...) 
#endif

inline void fast_io() { ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); };


template< int mod >
struct ModInt {
  int x;

  ModInt() : x(0) {}

  ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

  ModInt &operator+=(const ModInt &p) {
    if((x += p.x) >= mod) x -= mod;
    return *this;
  }

  ModInt &operator-=(const ModInt &p) {
    if((x += mod - p.x) >= mod) x -= mod;
    return *this;
  }

  ModInt &operator*=(const ModInt &p) {
    x = (int) (1LL * x * p.x % mod);
    return *this;
  }

  ModInt &operator/=(const ModInt &p) {
    *this *= p.inverse();
    return *this;
  }

  ModInt operator-() const { return ModInt(-x); }

  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }

  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }

  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }

  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }

  bool operator==(const ModInt &p) const { return x == p.x; }

  bool operator!=(const ModInt &p) const { return x != p.x; }

  ModInt inverse() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while(b > 0) {
      t = a / b;
      swap(a -= t * b, b);
      swap(u -= t * v, v);
    }
    return ModInt(u);
  }

  ModInt pow(int64_t n) const {
    ModInt ret(1), mul(x);
    while(n > 0) {
      if(n & 1) ret *= mul;
      mul *= mul;
      n >>= 1;
    }
    return ret;
  }

  friend ostream &operator<<(ostream &os, const ModInt &p) {
    return os << p.x;
  }

  friend istream &operator>>(istream &is, ModInt &a) {
    int64_t t;
    is >> t;
    a = ModInt< mod >(t);
    return (is);
  }

  static int get_mod() { return mod; }
};
int const mod = 1e9+7;
using modint = ModInt< mod >;

int X;
inline void input(){
    fast_io();
    cin >> X;
}

inline int solve(int S){
    int MaxN = S/3;
    modint ans = 0;
    vector<vector<modint>> dp(MaxN+1,vector<modint>(2010,0));
    dp[0][0] = 1;
    for (int i = 0; i < MaxN; i++)
    {
        for (int sum = 0; sum <= S; sum++)
        {
            if(sum==0) dp[i+1][sum] = dp[i][sum];
            else dp[i+1][sum] = dp[i+1][sum-1] + dp[i][sum];
        }
    }

    for (int n = 1; n <= MaxN; n++)
    {
        int T = S-3*n;
        ans += dp[n][T];
    }
    cout << ans << ",";    
    return 0;
}   

int fast_solve(int x){
  int ans[2020] =
  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  };
  cout << ans[x] << "\n";
  return 0;
}

int test(){
  for (int i = 0; i <= 2000; i++) solve(i);
  return 0;
}

int main()
{
    input();
    // solve(X);
    fast_solve(X);
    return 0;
}


Measured memory_bytes: 3584