/*
Telebe of Adicto && Mamedov yani AzeTurk810
I see humans but no humanity
*/
#include <iostream>
#include <vector>
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
using ll = long long;
using namespace std;
#define ln '\n'
#define INFi 1e9
#define INFll 1e18
#define int ll
constexpr int MOD = 1e9 + 7;
void solve() {
int n , cs , cf;
cin >> n >> cs >> cf;
vector< vector< int > > dp(n + 1 , vector< int > (n + 1,0));
dp[1][1] = 1;
int say = 0;
for(int i = 1;i <= n;i++) {
if(i == cs || i == cf)
say++;
for(int j = 1;j < i;j++) {
if(i == cs || i == cf) {
dp[i][j + 1] += dp[i - 1][j];
dp[i][j] += dp[i - 1][j];
dp[i][j + 1] %= MOD;
} else {
dp[i][j + 1] += (j + 1 - say) * dp[i - 1][j];
dp[i][j - 1] += dp[i - 1][j] * (j - 1);
dp[i][j - 1] %= MOD;
dp[i][j + 1] %= MOD;
}
dp[i][j] %= MOD;
}
}
cout << dp[n][1] << ln;
}
// Attack on titan<3
signed main() {
ios::sync_with_stdio(0);
cin.tie(nullptr);
int t = 1;
// cin >> t;
for(int cases = 0 ; cases < t;cases ++) {
solve();
}
}
// Just Imaginary
