#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
ll dp[2][2][2001][2001];
const int MOD = 1e9+7;
int n,s,e;
ll solve(int i,ll cnt,int lf,int rg){
if(cnt<0)return 0;
if(dp[lf][rg][i][cnt] != -1)return dp[lf][rg][i][cnt];
if(i==n)return (!cnt && lf && rg);
ll res = 0;
if(i != s && i != e){
if(i==n-1)res+=solve(i+1,cnt,lf,rg);
else{
res+=solve(i+1,cnt+1,lf,rg); //single cc , > s <
res+=solve(i+1,cnt-1,lf,rg) * 1LL *(cnt) * 1LL * (cnt-1)%MOD; //merge cc , < s >
if(lf)res+=solve(i+1,cnt-1,lf,rg) * 1LL * cnt;
if(rg)res+=solve(i+1,cnt-1,lf,rg) * 1LL * cnt;
}
}
if(i==s){
if(i==n-1)res+=solve(i+1,cnt,1,rg);
else{
res+=solve(i+1,cnt,1,rg); //s <
res+=solve(i+1,cnt-1,1,rg) * 1LL * cnt; //s > ... <
}
}
if(i==e){
if(i==n-1)res+=solve(i+1,cnt,lf,1);
else{
res+=solve(i+1,cnt,lf,1); //s <
res+=solve(i+1,cnt-1,lf,1) * 1LL * cnt; //s > ... <
}
}
res%=MOD;
return dp[lf][rg][i][cnt] = res;
}
int main()
{
cin>>n>>s>>e;
s--;
e--;
for(int i=0;i<=n;i++){
for(int j=0;j<=n;j++){
for(int k=0;k<4;k++){
dp[k&1][k/2][i][j] = -1;
}
}
}
/*
int ans = 0;
vector<int>v;
for(int i=0;i<n;i++)v.push_back(i);
while(true){
bool ok = 1;
if(v[0] != s || v[n-1] != e)ok = 0;
for(int i=0;i+2<n;i++){
if(v[i] < v[i+1] && v[i+1] < v[i+2])ok = 0;
if(v[i] > v[i+1] && v[i+1] > v[i+2])ok = 0;
}
ans+=ok;
if(!next_permutation(v.begin(),v.end()))break;
}
cout<<ans<<'\n';
* */
cout<<solve(0,0,0,0);
}
