#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
#define all(v) v.begin(),v.end()
#define Gondozu ios::sync_with_stdio(false);cout.tie(NULL);cin.tie(NULL);
using namespace std;
using ll = long long;
using pi = pair<int, int>;
using vi = vector<int>;
using vpi = vector <pair<int, int>>;
using vvi = vector <vector<int>>;
const int OO = 1e9 + 5;
const int N = 2e3 + 5, MOD = 1e9+7;
int n, s, e;
ll dp[N][N];
ll add(ll a, ll b) {
a += b;
if (a >= MOD) a -= MOD;
return a;
}
ll mul(ll a, ll b) { return a * b % MOD; }
void TC()
{
cin >> n >> s >> e;
dp[0][0] = 1;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= n; ++j) {
ll &cur = dp[i][j];
if(i == s || i == e){
cur = add(dp[i-1][j], dp[i-1][j-1]);
continue;
}
cur = add(mul(dp[i-1][j+1], j), mul(dp[i-1][j-1], max(0,j - (i>s) - (i>e))));
}
}
cout << dp[n][1];
}
int32_t main() {
Gondozu
int t = 1;
// cin >> t;
while (t--) {
TC();
cout << '\n';
}
return 0;
}
