#include<iostream>
#define M 1000000007
#define MAX_N 1000000
using namespace std;
typedef long long ll;

ll fact_n[MAX_N + 1], fact_inv[MAX_N + 1];

ll mod_pow(ll a, ll n) {
	ll x = 1;
	while (n > 0) {
		if (n & 1) x = x * a % M;
		a = a * a % M;
		n >>= 1;
	}
	return x;
}


ll combination(int n, int r) {
	if (n == 0 && r == 0) return 1;
	else if (n < r || n < 0) return 0;

	ll com = fact_n[n] * fact_inv[r] % M;
	return com * fact_inv[n - r] % M;
}



int main()
{
	int n, j;
	ll com = 0;
	cin >> n;

	fact_n[0] = fact_inv[0] = 1;
	for (int i = 1;i <= MAX_N;i++) {
		fact_n[i] = fact_n[i - 1] * i % M;
		fact_inv[i] = mod_pow(fact_n[i], M - 2);
	}

	for (int i = 0;i <= n;i++) {
		if (n - 2 * i >= 0) {
			j = (n - 2 * i) / 3;
			com += combination(i + j, i) % M;
		}
	}

	cout << com % M << endl;
    return 0;
}