#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define ff first
#define ss second
#define pb push_back
using namespace std;
template <int MOD>
class Modular {
private:
int val;
static const int mod = MOD;
Modular inverse (const Modular &A) {
Modular u = 0, v = 1;
int a = A.val;
int b = mod;
while(a != 0) {
int t = b / a;
b -= t * a; swap(b, a);
u -= t * v; swap(u, v);
}
return (b == 1) ? u : 0;
}
public:
explicit operator int() const {
return val;
}
Modular() { val = 0; }
Modular(ll x) {
val = x % mod;
if(val < 0) val += mod;
}
friend bool operator==(const Modular &A, const Modular &B) { return A.val == B.val; }
friend bool operator!=(const Modular &A, const Modular &B) { return A.val != B.val; }
friend bool operator<(const Modular &A, const Modular &B) { return A.val < B.val; }
friend bool operator>(const Modular &A, const Modular &B) { return A.val > B.val; }
Modular &operator+=(const Modular &A) { val += A.val; val %= mod; return *this; }
Modular &operator-=(const Modular &A) { val -= A.val; if(val < 0) val += mod; return *this; }
Modular &operator*=(const Modular &A) { val = (int)((ll)val * A.val % mod); return *this; }
Modular &operator/=(const Modular &A) { return *this *= inverse(A); }
Modular operator-() const { return Modular(-val); }
Modular &operator++() { return *this += 1; }
Modular &operator--() { return *this -= 1; }
friend Modular operator+(Modular A, const Modular &B) { return A += B; }
friend Modular operator-(Modular A, const Modular &B) { return A -= B; }
friend Modular operator*(Modular A, const Modular &B) { return A *= B; }
friend Modular operator/(Modular A, const Modular &B) { return A /= B; }
friend istream& operator>>(istream& stream, Modular &A) { ll x; stream >> x; A = Modular(x); return stream; }
friend ostream& operator<<(ostream& stream, Modular &A) { return stream << A.val; }
};
const int N = 2000;
const int mod = 1e9 + 7;
const int INF = 1e9 + 1;
using mint = Modular<mod>;
mint dp[N + 5][N + 5];
int main() {
int n, s, e;
cin >> n >> s >> e;
dp[1][1] = 1;
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= i; j++) {
if(i + 1 == s || i + 1 == e) {
dp[i + 1][j + 1] += dp[i][j];
dp[i + 1][j] += dp[i][j];
continue;
}
int points;
// Add as component
points = j + 1;
if(s <= i) points--;
if(e <= i) points--;
dp[i + 1][j + 1] += dp[i][j] * points;
// Marge components
points = j - 1;
dp[i + 1][j - 1] += dp[i][j] * points;
}
}
cout << dp[n][1] << " ";
// vector<int> vec;
// for(int i = 1; i <= n; i++) {
// vec.pb(i);
// }
// int cnt = 0;
// do {
// bool isGood = true;
// if(vec[0] != s || vec.back() != e) continue;
// for(int i = 2; i < vec.size(); i++) {
// if(vec[i - 2] < vec[i - 1] && vec[i - 1] < vec[i]) {
// isGood = false;
// break;
// }
// if(vec[i - 2] > vec[i - 1] && vec[i - 1] > vec[i]) {
// isGood = false;
// break;
// }
// }
// if(isGood) cnt++;
// }while(next_permutation(vec.begin(), vec.end()));
// cout << cnt << " ";
}
