#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 2005;
int dp[N][N];
const int mod = 1e9+7;
int add(int a,int b){
return (a + b) % mod;
}
int mul(int a,int b) {
return (a * b) % mod;
}
int32_t main() {
int n,st,en,diff=0;
cin >> n >> st >> en;
dp[1][1] = 1;
for(int i = 2;i<=n;i++) {
for(int j = 1;j<=i;j++) {
if(i == st || i == en) {
dp[i][j]=add(dp[i-1][j-1],dp[i-1][j]);
} else {
dp[i][j]=add(mul(dp[i-1][j-1],j-(i>st)-(i>en)),mul(dp[i-1][j+1],j));
}
// cerr << dp[i][j] << " ";
}
// cerr<<'\n';
}
cout << dp[n][1];
}
/*
no 3 can be increasing 2x or decreasing 2x
want to use the same update so force structure into the problme
*/
