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

int main(){
	int N,A,B;
	int p = 998244353;
	cin >> N >> A >> B;
	vector<int> factorial_modp(N+1);
	factorial_modp[0] =1;
	for(int i=1;i<=N;i++){
		factorial_modp[i] = (i * factorial_modp[i-1]) % p;
	}
	if(A == B){
		cout << (factorial_modp[N]-2*factorial_modp[N-1])%p << endl;
	} else {
		cout << (factorial_modp[N]-2*factorial_modp[N-1]+factorial_modp[N-2])%p << endl;
	}
}