#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()
const ll mod=1e9+7;
int main(){
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
ll n,cs,cf;
cin>>n>>cs>>cf;
vector<ll>v(n);
iota(all(v),1);
ll ans=0;
do{
if(v[0]!=cs||v[n-1]!=cf) continue;
bool ok=true;
for(ll i=1;i<n-1;i++){
if(max(v[i-1],v[i+1])<v[i]||min(v[i-1],v[i+1])>v[i]) continue;
ok=false;
}
if(ok) ans++;
}while(next_permutation(all(v)));
cout<<ans;
}
