#include <iostream>
#include <fstream>
#define Nmax 15000003
using namespace std;
ifstream fin("12perm.in");
ofstream fout("12perm.out");
int dp[Nmax],n,l=0;
const int mod=1048576;
int main()
{
    fin>>n;
    if(n==1)
    {
        fout<<1;
        return 0;
    }
    dp[2]=dp[1]=2;dp[3]=6;
    for(int i=4;i<=n;i++,l+=1)
        dp[i]=(dp[i-1]+dp[i-3]+i+l)%mod;
    fout<<dp[n];
    return 0;
}