/*
Author : DeMen100ns (Vo Khac Trieu)
School: University of Science, VNU-HCM
Aim:
- International Grandmaster Codeforces (2600)
- ICPC World Final 2025
*/
#include <bits/stdc++.h>
#define int long long
using namespace std;
const long long INF = numeric_limits<long long>::max() / 2;
const int INF_int = 1e9 + 7;
const int MOD = 1e9 + 7;
void solve(){
int n, cs, cf; cin >> n >> cs >> cf;
vector <vector<array<int, 3>>> dp(n + 1, vector<array<int, 3>>(n + 1, {0, 0, 0}));
dp[0][0][0] = 1;
for(int i = 0; i < n; ++i){
if (i + 1 == cs || i + 1 == cf){
for(int c = 0; c <= i; ++c){
for(int e = 0; e < 2; ++e){
dp[i][c][e] %= MOD;
dp[i + 1][c][e + 1] += dp[i][c][e] % MOD;
dp[i + 1][c + 1][e + 1] += dp[i][c][e] % MOD;
}
}
} else {
for(int c = 0; c <= i; ++c){
for(int e = 0; e <= 2; ++e){
dp[i][c][e] %= MOD;
dp[i + 1][c + 1][e] += dp[i][c][e] * (c + 1 - e) % MOD;
dp[i + 1][c - 1][e] += dp[i][c][e] * (c - 1) % MOD;
}
}
}
}
cout << dp[n][1][2] % MOD << '\n';
}
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0);
int t = 1; // cin >> t;
for(int test = 1; test <= t; ++test){
solve();
}
}
