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

void fast_io() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
}

#include <atcoder/modint>
using mint = atcoder::modint998244353;
int main() {
	fast_io();
	int n, a, b;
	cin >> n >> a >> b;
	vector<mint> facts(n + 1);
	facts[0] = 1;
	for (int i = 1; i <= n; i++) {
		facts[i] = facts[i - 1] * i;
	}
	mint ans = facts[n] - 2 * facts[n - 1];
	if (a != b) {
		ans += facts[n - 2];
	}
	cout << ans.val() << endl;
}