#include <iostream>
#include <algorithm>
using namespace std;
int n, dp[4009], ndp[4009], mod = 1000000007;
void calc() {
	for (int i = 0; i < n - 1; i++) {
		int x = (i > 0 ? i : 1);
		for (int j = 0; j < x; j++) {
			ndp[0] += dp[j];
			if (ndp[0] >= mod) ndp[0] -= mod;
		}
		for (int j = 1; j < n; j++) {
			ndp[j] = ndp[j - 1] + dp[j + x - 1];
			if (ndp[j] >= mod) ndp[j] -= mod;
		}
		for (int j = 0; j < n; j++) dp[j] = ndp[j], ndp[j] = 0;
	}
}
int main() {
	cin >> n;
	fill(dp, dp + n, 1);
	calc();
	int ret = 0;
	for (int i = 0; i < n; i++) ret = (ret + dp[i]) % mod;
	fill(dp, dp + n, 0); dp[0] = 1;
	calc();
	cout << (ret - dp[n - 1] + mod) % mod << endl;
	return 0;
}