#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

    const ll modc = 998244353;
    ll N, A, B;
    cin >> N >> A >> B;
    vector<ll> p(N+1);
    p[0] = 1;
    p[1] = 1;
    for (ll i=2; i<=N; i++){
        p[i] = (p[i-1] * i) % modc;
        p[i] %= modc;
    }

    if (A != B){
        cout << (p[N] + modc*2 - p[N-1]*2 + p[N-2]) % modc << endl;
    }
    else{
        cout << (p[N] + modc*2 - p[N-1]*2) % modc << endl;
    }

    return 0;
}