// Problem:No.535 ????????
// Contest:yukicoder
// URL:https://yukicoder.me/problems/no/535
// Memory Limit:512 MB
// Time Limit:2000 ms
// Codeforces/Luogu Account:Butterfly_qwq
// Atcoder Account:Super_agg
// CP Duel Rating:2034
// Start Coding:03-14 15:00
// 
// Powered by CP Editor (https://cpeditor.org)

#include<bits/stdc++.h>
using namespace std;
const int N=2005,mod=1e9+7;
int n,ans,s[N],dp[N][N];
int Mod(int x){return x-(x>=mod)*mod+(x<0)*mod;}
void solve()
{
	for(int i=1;i<n;i++)
	{
		s[0]=0;
		for(int j=1;j<=n;j++)s[j]=Mod(s[j-1]+dp[i-1][j]);
		for(int j=1;j<=n;j++)dp[i][j]=s[min(n,j+max(0,i-2))];
	}
}
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++)dp[0][i]=1;solve();
	for(int i=1;i<=n;i++)ans=Mod(ans+dp[n-1][i]);
	for(int i=2;i<=n;i++)dp[0][i]=0;solve();
	cout<<Mod(ans-dp[n-1][n]);
}