3 3 1
 300 2 300
 4000 4000 1
 4000 4000 100
 4 2 3
 3 300 300
 4000 100 4000
 3 300 1
 300 300 1
 4000 1000 3000
 3 2 4000
 4 3 2
 3 2 300
 4000 3998 2
 100 200 300
 300 300 300
 3 3 3
 10 10 10
 10 4 9
 239 300 231
 4000 2 3998
 200 100 300
 4000 2000 2000
 4000 4000 4000
 10 7 5
 4000 100 3900
 3 4000 4000

12
 775907030
 63263244
 994443885
 24
 496527918
 908339579
 828107078
 775907030
 876839920
 938379934
 48
 196174631
 296557186
 316471646
 375912430
 72
 318389383
 135283173
 774612666
 686088712
 949581532
 310481606
 997463324
 130636800
 221262673
 680114446

#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <tr1/unordered_map>
#include <tr1/unordered_set>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>

using namespace std;
using namespace std::tr1;

typedef long long ll;
typedef pair<int, int> pii;
#define foreach(v,c) for (typeof((c).begin()) v = (c).begin(); v != (c).end(); ++v)
#define rep(i,s,e) for (int i = (s); i < (e); ++i)

int dx[]={0,0,1,-1,1,-1,1,-1};
int dy[]={-1,1,0,0,1,-1,-1,1};
const int mod = 1e9+7;

int n, w, b;
static ll C[5000][5000];
static ll fac[5000];
int main() {
	rep(i,0,4500) {
		C[i][0] = 1;
		rep(j,1,i+1) C[i][j] = (C[i-1][j] + C[i-1][j-1]) %mod;
	}
	fac[0] = 1;
	rep(i,1,4500) fac[i] = i*fac[i-1]%mod;
	cin >> n >> w >> b;
	ll ans = 0;
	for (int good = 2; good < n; ++good) {
    ll res = C[w-1][good-1] * C[b-1][n-good-1] % mod
			     * fac[w] % mod
					 * fac[b] % mod;
		//cout << "good=" << good << " res=" << res << endl;
		ans = (ans+res*(good-1))%mod;
	}
	cout << ans << endl;
}
