/*For today, you happen to be the defeated. But what will you become tomorrow?*/
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define int long long int
#define dbg if(debugg)
#define F first
#define S second
bool debugg = false;
template <typename T>
using order_set = tree<T, null_type,less<T>, rb_tree_tag,tree_order_statistics_node_update>;
template <typename T>
using minheap = priority_queue<T, vector<T>, greater<T>>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int mod = 1000000007;
int n, s, e;
int dp[2002][2002][2][2];
int f(int pos, int comp, int p, int q)
{
if(comp <= 0) return 0;
if(pos == 0) return comp == 1;
int &ans = dp[pos][comp][p][q];
if(~ans) return ans;
ans = 0;
if(pos == s){
ans += f(pos - 1, comp + 1, 1, q) + f(pos - 1, comp, 1, q);
ans %= mod;
}
else if(pos == q){
ans += f(pos - 1, comp + 1, p, 1) + f(pos - 1, comp, p, 1);
ans %= mod;
}
else{
ans += f(pos - 1, comp - 1, p, 1) * (comp - 1);
ans += f(pos - 1, comp + 1, p, q) * (comp + 1 - p - q);
ans %= mod;
}
return ans;
}
void solve()
{
cin >> n >> s >> e;
memset(dp, -1, sizeof(dp));
cout << f(n - 1, 1, n == s, n == e);
}
int32_t main()
{
ios::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
while(t--){
solve();
}
return 0;
}
