#define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <math.h>
#include <cmath>
#include <stack>
#include <map>
#include <set>
#include <numeric>
#include <iomanip>
#include <climits>
#include <functional>
#include <cassert>
#include <tuple>
using namespace std;
using ll = long long;

int N, A, B;
ll mod = 998244353;

int main() {

    cin >> N >> A >> B;
    vector<ll> kai(N+1, 0);
    kai[0] = 1;

    for(int i = 1; i <= N; ++i) {
        kai[i] = kai[i-1]*i;
        kai[i] %= mod;
    }

    ll ans = kai[N]-kai[N-1]*2+(A!=B ? kai[N-2] : 0);
    ans %= mod;
    ans = (ans+mod)%mod;

    cout << ans << endl;

}