#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pi pair<int,int>
#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define getunique(v) {sort(v.begin(), v.end()); v.erase(unique(v.begin(), v.end()), v.end());}
const ll INF = -1;
const int mx = 1e5+5;
const int modulo =1e9+7;
mt19937 mt;
ll dp[2005][2005];
void solve(){
int n,s,e;
cin>>n>>s>>e;
dp[1][1] = 1;
if(s>e) swap(s,e);
rep(x,2,n+1){
rep(y,1,x+1){
if(dp[x-1][y]==0) continue;
if(x==s){
dp[x][y+1] = (dp[x][y+1]+(dp[x-1][y]))%modulo;
dp[x][y] = (dp[x][y]+(dp[x-1][y]))%modulo;
continue;
}
else if(x==e){
dp[x][y+1] = (dp[x][y+1]+(dp[x-1][y]))%modulo;
dp[x][y] = (dp[x][y]+(dp[x-1][y]))%modulo;
continue;
}
if(x<s){
dp[x][y+1] = (dp[x][y+1]+(dp[x-1][y]*(y+1))%modulo)%modulo;
dp[x][y-1] = (dp[x][y-1]+(dp[x-1][y]*(y-1))%modulo)%modulo;
}
else if(x>s && x<e){
dp[x][y+1] = (dp[x][y+1]+(dp[x-1][y]*(y+1-1))%modulo)%modulo;
dp[x][y-1] = (dp[x][y-1]+(dp[x-1][y]*(y-1))%modulo)%modulo;
}else{
dp[x][y+1] = (dp[x][y+1]+(dp[x-1][y]*(y+1-2))%modulo)%modulo;
dp[x][y-1] = (dp[x][y-1]+(dp[x-1][y]*(y-1))%modulo)%modulo;
}
}
}
// rep(x,0,n+1){
// rep(y,0,n+1){
// cout<<dp[x][y]<<" ";
// }cout<<"\n";
// }
cout<<dp[n][1]<<"\n";
}
int main(){
ios_base ::sync_with_stdio(0), cin.tie(0);
clock_t start, end;
start = clock();
int t = 1;
// cin >> t;
// int x=0;
while (t-->0)
{
//cout<<"Case #"<<x<<": ";
solve();
// x++;
}
end = clock();
cerr << double(end - start) / double(CLOCKS_PER_SEC) << '\n';
}
