#include <bits/stdc++.h>
using namespace std;
#define ll long long
const ll MOD = 1000000007;
ll addmod(ll a, ll b){
a += b;
if(a >= MOD) a -= MOD;
return a;
}
ll mulmod(ll a, ll b){
return (a * b) % MOD;
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, s, t;
if(!(cin >> n >> s >> t)) return 0;
vector<vector<ll>> f(n+2, vector<ll>(n+3, 0));
f[1][1] = 1;
for(int i = 2; i <= n; ++i){
if(i != s && i != t){
for(int j = 1; j <= n; ++j){
ll avail = j - (i > s) - (i > t); // replaced int with ll
if(avail > 0){
f[i][j] = addmod(f[i][j], mulmod(f[i-1][j-1], avail));
}
if(j+1 <= n){
f[i][j] = addmod(f[i][j], mulmod(f[i-1][j+1], j));
}
}
} else {
for(int j = 1; j <= n; ++j){
f[i][j] = addmod(f[i][j], f[i-1][j-1]);
f[i][j] = addmod(f[i][j], f[i-1][j]);
}
}
}
cout << f[n][1] % MOD << '\n';
return 0;
}
