#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

template< int mod >
struct Fp {
    int x;
    Fp() : x(0) {}
    Fp(int64_t y) : x(y >= 0 ? y % mod : (mod + y % mod) % mod) {}
    Fp &operator+=(const Fp &p) { if((x += p.x) >= mod) x -= mod; return *this; }
    Fp &operator-=(const Fp &p) { if((x += mod - p.x) >= mod) x -= mod; return *this; }
    Fp &operator*=(const Fp &p) { x = (int)(1LL * x * p.x % mod); return *this; }
    Fp &operator/=(const Fp &p) { *this *= p.inv(); return *this; }
    Fp operator-() const { return Fp(-x); }
    Fp operator+(const Fp &p) const { return Fp(*this) += p; }
    Fp operator-(const Fp &p) const { return Fp(*this) -= p; }
    Fp operator*(const Fp &p) const { return Fp(*this) *= p; }
    Fp operator/(const Fp &p) const { return Fp(*this) /= p; }
    bool operator==(const Fp &p) const { return x == p.x; }
    bool operator!=(const Fp &p) const { return x != p.x; }

    Fp inv() 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 Fp(u);
    }

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

    friend ostream &operator<<(ostream &os, const Fp &p) { return os << p.x; }
    friend istream &operator>>(istream &is, Fp &a) {
        int64_t t;
        is >> t;
        a = Fp< mod > (t);
        return (is);
    }

    static int get_mod() { return mod; }
};

using mint = Fp<1000000007>;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    int N; cin >> N;
    vector<mint> dp(N + 1);
    dp[1] = 1;
    dp[2] = dp[3] = 2;
    for(int i = 4; i <= N; i++) dp[i] = dp[i - 2] + dp[i - 3];
    cout << dp[N] << endl;
}