#include <bits/stdc++.h>
#define append push_back
#define int long long
using namespace std;
const int N=2e3+10;
const int mod=1e9+7;
int dp[N][N][5];
void solve(){
int n,s,e;
cin>>n>>s>>e;
dp[1][1][s==1 or e==1] = 1;
for(int i=2;i<=n;i++){
for(int j=1;j<=i;j++){
if(i==s or i==e){
for(int k=1;k<=2;k++) dp[i][j][k]=(dp[i-1][j-1][k-1]+dp[i-1][j][k-1])%mod;
}
else{
for(int k=0;k<=2;k++) dp[i][j][k]=(dp[i-1][j-1][k]*(j-k)*(j>=k)+dp[i-1][j+1][k]*j)%mod;
}
}
}
cout<<dp[n][1][2];
}
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int T = 1;
// cin >> T;
while (T--)
solve();
}
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