#include<atcoder/all>
using namespace std;

int main(){
    int n;
    cin >> n;
    atcoder::modint1000000007 dp[n+1][n+4];
    for(int i=0; i<=n ; i++)dp[0][i]=dp[i][i]=1;
    for(int i=3; i<=n ; i++){
        for(int j=i-1; j>=3; j--){
            dp[i][j]=dp[i][j+1]+dp[i-j][j];
        }
    }
    cout<<dp[n][3].val()<<endl;
}