/*
in the name of god
*/
//#pragma GCC optimize("Ofast,O3,unroll-loops")
//#pragma GCC target("avx,avx2,fma")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4.1,sse4.2,sse4a,avx,avx2,popcnt,tune=native")
#include <bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> pii;
typedef pair<long long ,long long> pll;
typedef long long ll ;
#define File freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);
#define all(V) V.begin(),V.end()
#define setprec(x) fixed << setprecision(x)
#define Mp(a,b) make_pair(a,b)
#define len(V) (int)(V.size())
#define sep ' '
#define endl '\n'
#define pb push_back
#define fi first
#define sec second
#define popcount(x) __builtin_popcount(x)
#define lid u<<1
#define rid (lid)|1
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll N = 2e3 + 10,SQ=320,LOG=31;
const ll inf = 2e9 , MD = 1e9 + 7;
inline ll md(ll x){ x %= MD; return (x < 0 ? x + MD : x);}
int n ;
int s,e;
int dp[N][N][3];
int32_t main() {
ios_base::sync_with_stdio(false);cout.tie(0);cin.tie(0);
cin >> n >> s >> e;
dp[0][0][0] = 1;
for(int i = 0;i < n;i++){
for(int j = 0;j<n;j++){
for(int r =0 ;r < 3;r++){
if((i+1) == s || (i+1) == e){
if(r + 1 < 3) {
if(j) dp[i+1][j][r+1] = md(dp[i+1][j][r+1] + dp[i][j][r]);
dp[i+1][j+1][r+1] = md(dp[i+1][j+1][r+1] + dp[i][j][r]);
}
}
else{
dp[i+1][j+1][r] = md(dp[i+1][j+1][r] + md((j+1-r) * dp[i][j][r]));
if(j >= 2) dp[i+1][j-1][r] = md(dp[i+1][j-1][r] + md((j-1) * dp[i][j][r]));
}
}
}
}
cout << dp[n][1][2] << endl;
return 0;
}
