#include <bits/stdc++.h>
#define f first
#define s second
#define m_p make_pair
#define vec vector
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define pw(x) (1LL<<(x))
#define sz(x) (int)(x).size()
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
const int M=1e9+7;
void add(int &a,int b){
a+=b;
if(a>=M) a-=M;
else if(a<0) a+=M;
}
int mult(int a,int b){
return 1ll*a*b%M;
}
const int N=2e3+1;
int dp[N][N];
/// len,pos and last was left/right
signed main(){
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
int n,x,y;
cin>>n>>x>>y;--x;--y;
dp[0][0]=1;
// dp[1][1]=1;
for(int i=0 ;i<n;i++){
for(int c=0;c<=i;c++){
if(i==x || i==y){
/// if i just in beginning
add(dp[i+1][c],dp[i][c]);
add(dp[i+1][c+1],dp[i][c]);
}
else{
// /// if i choose between them
// int cnt=(i-1)-(c-1);
//
// add(dp[i+1][c],mult(dp[i][c],cnt));
/// if i make new comp
int w=c+1-(i>=x)-(i>=y);
add(dp[i+1][c+1],mult(dp[i][c],w));
if(c)
add(dp[i+1][c-1],mult(dp[i][c],c-1));
}
// cout<<dp[i][c]<<' ';
}
// cout<<endl;
}
cout<<dp[n][1];
return 0;
}
/*
5 14
3 7 1 5 10
1 3 5 7 10
11 2
aa
ab
aa
ca
aa
bc
ea
aa
ad
de
aa
*/
