#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
using u64 = unsigned long long;
#define REP(i, n) for (int i = 0; i < (i64)(n); ++i)
#define WHOLE(x) std::begin(x), std::end(x)
#define LEN(a) int((a).size())

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

template <typename T>
using V = std::vector<T>;
template <typename T>
vector<T> make_vec(size_t n, T a) {
  return vector<T>(n, a);
}
template <typename... Ts>
auto make_vec(size_t n, Ts... ts) {
  return vector<decltype(make_vec(ts...))>(n, make_vec(ts...));
}
template <typename T>
istream &operator>>(istream &is, vector<T> &a) {
  for (auto &x : a) is >> x;
  return is;
}
template <typename Container>
ostream &pprint(const Container &a, string_view sep = " ",
                string_view ends = "\n", ostream *os = nullptr) {
  if (os == nullptr) os = &cout;
  auto b = std::begin(a), e = std::end(a);
  for (auto it = std::begin(a); it != e; ++it) {
    if (it != b) *os << sep;
    *os << *it;
  }
  return *os << ends;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &a) {
  return pprint(a, ", ", "", &(os << "[")) << "]";
}
template <typename T>
ostream &operator<<(ostream &os, const set<T> &a) {
  return pprint(a, ", ", "", &(os << "{")) << "}";
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &a) {
  return pprint(a, ", ", "", &(os << "{")) << "}";
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &a) {
  return os << "(" << a.first << ", " << a.second << ")";
}

#ifdef ENABLE_DEBUG
template <typename T>
void debug(T value) {
  cerr << value;
}
template <typename T, typename... Ts>
void debug(T value, Ts... args) {
  cerr << value << ", ";
  debug(args...);
}
#define DEBUG(...)                              \
  do {                                          \
    cerr << " \033[33m (L" << __LINE__ << ") "; \
    cerr << #__VA_ARGS__ << ":\033[0m ";        \
    debug(__VA_ARGS__);                         \
    cerr << endl;                               \
  } while (0)
#else
#define debug(...)
#define DEBUG(...)
#endif

const int MOD = 1'000'000'007;

struct mint {
  int x;

  mint(long long val = 0) {
    if (val < 0) {
      long long k = (abs(val) + MOD - 1) / MOD;
      val += k * MOD;
    }
    assert(val >= 0);
    x = val % 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 = (x * (long long)a.x) % MOD;
    return *this;
  }
  mint pow(long long t) const {
    assert(t >= 0);
    mint base = *this;
    mint res = 1;
    while (t) {
      if (t & 1) res *= base;
      base *= base;
      t >>= 1;
    }
    return res;
  }
  // 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 mint &b) { return mint(a) += b; }
mint operator-(const mint &a, const mint &b) { return mint(a) -= b; }
mint operator*(const mint &a, const mint &b) { return mint(a) *= b; }
mint operator/(const mint &a, const mint &b) { return mint(a) /= b; }
bool operator==(const mint &a, const mint &b) { return a.x == b.x; }
bool operator!=(const mint &a, const mint &b) { return a.x != b.x; }
bool operator<(const mint &a, const mint &b) { return a.x < b.x; }
bool operator>(const mint &a, const mint &b) { return a.x > b.x; }
bool operator<=(const mint &a, const mint &b) { return a.x <= b.x; }
bool operator>=(const mint &a, const mint &b) { return a.x >= b.x; }
istream &operator>>(istream &is, mint &a) { return is >> a.x; }
ostream &operator<<(ostream &os, const mint &a) { return os << a.x; }

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int S;
  cin >> S;
  V<mint> dp(S + 1, mint(0));
  dp[0] = 1;
  for (int i = 3; i <= S; ++i) {
    dp[i] = dp[i - 1];
    if (i - 3 >= 0) dp[i] += dp[i - 3];
  }
  cout << dp[S] << endl;
}


Measured memory_bytes: 3508