#include <bits/stdc++.h>
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)

using namespace std;
using mint = modint998244353;

struct modfact {
  int n; vector<mint> d;
  modfact(): n(2), d({1,1}) {}
  mint operator()(int i) {
    while (n <= i) d.push_back(d.back()*n), ++n;
    return d[i];
  }
  mint operator[](int i) const { return d[i];}
} facts;

int main() {
    int n, a, b;
    cin >> n >> a >> b;
    
    mint ans = facts(n);
    ans -= facts(n-1)*2;
    if (a != b) ans += facts(n-2);
    
    cout << ans.val() << '\n';
    
    return 0;
}