#include <bits/stdc++.h>
using namespace std;
const long long MOD = 998244353;
int main(){
  int N, A, B;
  cin >> N >> A >> B;
  vector<long long> fact(N + 1);
  fact[0] = 1;
  for (int i = 1; i <= N; i++){
    fact[i] = fact[i - 1] * i % MOD;
  }
  long long ans = fact[N] + (MOD - fact[N - 1]) * 2;
  if (A != B){
    ans += fact[N - 2];
  }
  ans %= MOD;
  cout << ans << endl;
}