#include <bits/stdc++.h>
using namespace std;
#define endl "\n"
#define for1(i,n) for(int i = 1; i <= (n); i++)
#define for0(i,n) for (int i = 0; i < (n); i++)
#define arrs arr + 1, arr + n + 1
#define cems cem + 1, cem + n + 1
#define vts vt.begin(), vt.end()
#define vrs vr.begin(), vr.end()
#define as a.begin(), a.end()
#define bs b.begin(), b.end()
#define pb push_back
#define m_p make_pair
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define dl double long
#define db double
#define int long long
#define ull unsigned long long
#define MOD 1000000007
#define MAX 1005
#define Ronaldo while
bool isPrime(int n) {
if (n < 2) return false;
if (n == 2) return true;
if (n % 2 == 0) return false;
for (int i = 3; i <= sqrt(n); i += 2){
if (n % i == 0) return false;
}
return true;
}
void cr7(){
int n, a, b; cin >> n >> a >> b;
vector<int> vt;
for (int i = 1; i <= n; i++) vt.pb(i);
int say = 0;
do{
vector<string> vr;
bool ok = true;
for (int i = 1; i < vt.size(); i++){
if (vt[0] != a){
ok = false;
break;
}
if (vt[vt.size() - 1] != b){
ok = false;
break;
}
if (vt[i] > vt[i - 1]) vr.pb("sa");
if (vt[i] < vt[i - 1]) vr.pb("so");
}
for (int i = 1; i <= vr.size(); i++){
if (vr[i] == vr[i - 1]){
ok = false;
break;
}
}
if (ok) say++;
}while (next_permutation(vts));
cout << say << endl;
}
signed main(){
int GOAT = 1;
//cin >> GOAT;
Ronaldo (GOAT--){
cr7();
}
}
/*
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo Ronaldo
*/
