#include <bits/stdc++.h>
using namespace std;

#include <atcoder/modint>
using mint = atcoder::modint998244353;

int main() {
	mint n; { int x; cin >> x; n = x; }
	mint ans = 1 + n + n * (n - 1) / 6;
	cout << ans.val() << endl;
}