#include <bits/stdc++.h>
using namespace std;
//#define ACL
#ifdef ACL
#include <atcoder/all>
using namespace atcoder;
#endif
#define int int64_t
#define REP(i, n) for (int i = 0; (i) < (int)(n); ++ (i))
#define REP3(i, m, n) for (int i = (m); (i) < (int)(n); ++ (i))
#define REP_R(i, n) for (int i = (int)(n) - 1; (i) >= 0; -- (i))
#define REP3R(i, m, n) for (int i = (int)(n) - 1; (i) >= (int)(m); -- (i))
#define REPP(i, n) for (int i = 1; (i) < (int)(n+1); ++ (i))
#define REPR(i, n) for (int i = (int)(n) - 1; (i) >= 0; -- (i))
#define FOR(i, m, n) for(int i = m; i < n; i++)
#define FORR(i, m, n) for(int i=(m)-1; i>=(n); i--)
#define ALL(v) v.begin(), v.end()
#define endl "\n"
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
using Graph = vector<vector<int> >;
using WeightedGraph = vector<vector<pair<int, int> > >;
using LD = long double;
using VI = vector<int>;
using VVI = vector<vector<int> >;
using PII = pair<int, int>;
template <typename T> using V = vector<T>;
template <typename T> using VV = vector<vector<T> >;
template <typename T> using VVV = vector<vector<vector<T> > >;
void print() {cout << endl;}
template <typename Head, typename... Tail> void print(Head&& head, Tail&&... tail) {cout << head; if (sizeof...(tail) != 0) cout << " ";print(forward<Tail>(tail)...);}
template <typename T> void print(vector<T> &vec) {for (auto& a : vec) {cout << a; if (&a != &vec.back()) cout << " ";} cout << endl;}
template <typename T> void print(vector<vector<T>> &df) { for (auto& vec : df) { print(vec);}}
template <typename T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template <typename T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template <typename T> void SORT (T &v) {sort(v.begin(), v.end());}
template <typename T> void SORTR (T &v) {sort(v.begin(), v.end(), greater<>());}
template <typename T> T GCD(T x,T y) {return __gcd(x,y);}
template <typename T> T LCM(T x,T y) {return x/__gcd(x,y)*y;}
template <typename T> int SZ(T v) {return v.size();}
template <typename T> T PCNT(T x) {return __builtin_popcountll(x);}
template <typename T> T BIT(T x) {return 1LL<<(x);}
int INF = 2000000000;
long double PI = acosl(-1);
int MOD = 1000000007;

struct mint {
    int x;
    mint(int 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(int t) const {
        if (!t) return 1;
        mint a = pow(t>>1);
        a *= a;
        if (t&1) a *= *this;
        return a;
    }
    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, const mint& a) { return is >> a.x;}
ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}

int modpow(int N, int M){return M ? modpow(N * N % MOD, M / 2) * (M % 2 ? N : 1) % MOD : 1;}
int modcomb(int N,int M){ int x = 1, y = 1; for(int i = 1; i <= M; i++) {x = x * (N-i+1) % MOD; y = y * i % MOD;} return x * modpow(y, MOD-2) % MOD;}
int modperm(int N, int M){ int P = 1; for (int i = 1; i <= M; i++) P = P * (N-i+1) % MOD; return P % MOD;}


int32_t main() {
    chrono::system_clock::time_point start_time, end_time;
    start_time = chrono::system_clock::now();
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(10);
    mint ans = 0, res = 0;
    
    int S;
    cin >> S;
    for (int i = 1; S - 3*i >= 0; i++) {
        ans += modcomb(S-3*i+i-1, i-1);
    }
    cout << ans << endl;

    
    



    end_time = chrono::system_clock::now();
    assert(chrono::duration_cast<chrono::milliseconds>(end_time-start_time).count() < 2500);
    return 0;
}

/*
cd ~/Desktop/Programming/AtCoder/contest/abc178/abc178_d && sh shellscripts/test_cpp.sh
cd ~/Desktop/Programming/AtCoder/contest/abc178/abc178_d && sh shellscripts/etest_cpp.sh
cd ~/Desktop/Programming/AtCoder/contest/abc178/abc178_d && sh shellscripts/submit_cpp.sh
*/


Measured memory_bytes: 3580