#include <functional>
#include <iostream>
#include <optional>
#include <vector>
#include <atcoder/modint>

using namespace std;
using Mint = atcoder::modint1000000007;

int main()
{
	int N;
	cin >> N;
	vector<vector<optional<Mint>>> DP(N + 1, vector<optional<Mint>>(N + 1));
	function<Mint(int, int)> f = [&](int a, int b)
	{
		if (a == 0)
			return Mint(1);
		if (b > a)
			return Mint(0);
		if (DP[a][b])
			return *DP[a][b];
		return *(DP[a][b] = f(a - b, b) + f(a, b + 1));
	};
	cout << f(N, 3).val() << endl;
}