#include <bits/stdc++.h>
using namespace std;
#if __has_include("all.hpp")
#include "all.hpp"
#else
#include <atcoder/all>
#endif
using namespace atcoder;
using mint=modint998244353;
int main(void){
    long long n;
    cin>>n;
    mint nm=n;
    mint ans=(nm*nm+5*nm+6)/6;
    cout<<ans.val()<<endl;
    return 0;
}