#include<bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
#define ll long long
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
inline ll gen_random(ll l, ll r) {
return uniform_int_distribution<ll>(l, r)(rng);
}
#define test cout<<"Test_Round\n"
#define pb push_back
#define pi pair<int,int>
#define pii pair<ll,ll>
#define all(x) x.begin(),x.end()
#define rsort(x) sort(x.rbegin(),x.rend())
#define fastio ios_base::sync_with_stdio(false),cin.tie(NULL)
#define ull unsigned long long
#define db double
#define pai acos(-1)
#define bitcheck(n,k) ((n&(1ll<<k))>0ll)
#define ff first
#define ss second
bool primecheck(ll x){for(ll i=2;i*i<=x;i++)if(x%i==0)return 0;return 1;}
template<typename type>
void show(vector<type>&a){
int N=a.size();
for(int i=0;i<N;i++){
cout<<a[i]<<" ";
}cout<<"\n";
}
int cs=0;
void Case(){
cout<<"Case "<<++cs<<": ";
}
const ll mod=1e9+7;
const int mxx=2e3+2;
ll dp[mxx][mxx];
void solve(){
int n,s,e;
cin>>n>>s>>e;
dp[0][0]=1;
for(int i=1;i<=n;i++)
{
if(!(i==s||i==e))
{
if(i<min(s,e))
{for(int j=1;j<=i;j++){
dp[i][j]=(dp[i-1][j-1]*j+dp[i-1][j+1]*(j))%mod;
}
}
else if(i>max(s,e)){
for(int j=1;j<=i;j++){
dp[i][j]=(max(0ll,dp[i-1][j-1]*(j-2))+dp[i-1][j+1]*(j))%mod;
}
}
else if(i>s){
for(int j=1;j<=i;j++){
dp[i][j]=(dp[i-1][j-1]*(j-1)+dp[i-1][j+1]*(j))%mod;
}
}
else{
for(int j=1;j<=i;j++){
dp[i][j]=(dp[i-1][j-1]*(j-1)+dp[i-1][j+1]*(j))%mod;
}
}
}
else if(i==s){
for(int j=1;j<=i;j++){
dp[i][j]=(dp[i-1][j-1]+dp[i-1][j])%mod;
}
}
else{
for(int j=1;j<=i;j++){
dp[i][j]=(dp[i-1][j-1]+dp[i-1][j])%mod;
}
}
}
cout<<dp[n][1]<<"\n";
}
int main(){
fastio;
// freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
int t=1;//cin>>t;
while(t--){
solve();
}
}
