#include <bits/stdc++.h>
using namespace std;
const long long MOD=1e9+7;
const long long MX=2100;
long long dp[MX][MX][4]={0};
int main()
{
cin.tie(0);
ios_base::sync_with_stdio(0);
long long n,s,f;
cin>>n>>s>>f;
dp[1][1][0]=1;
for(long long i=1;i<n;i++)
{
for(long long k=1;k<n;k++)
{
if((i+1)<=s)
{
dp[i+1][k][2]=(dp[i+1][k][2]+dp[i][k][0])%MOD;
dp[i+1][k][3]=(dp[i+1][k][3]+dp[i][k][1])%MOD;
}
if((i+1)<=f)
{
dp[i+1][k][1]=(dp[i+1][k][1]+dp[i][k][0])%MOD;
dp[i+1][k][3]=(dp[i+1][k][3]+dp[i][k][2])%MOD;
}
if((i+1)!=s && (i+1)!=f)
{
dp[i+1][k-1][0]=(dp[i+1][k-1][0]+dp[i][k][0]*(k-1))%MOD;
dp[i+1][k-1][1]=(dp[i+1][k-1][1]+dp[i][k][1]*(k-1))%MOD;
dp[i+1][k-1][2]=(dp[i+1][k-1][2]+dp[i][k][2]*(k-1))%MOD;
dp[i+1][k-1][3]=(dp[i+1][k-1][3]+dp[i][k][3]*(k-1))%MOD;
}
if((i+1)==s)
{
dp[i+1][k+1][0]=(dp[i+1][k+1][0]+dp[i][k][0])%MOD;
dp[i+1][k+1][1]=(dp[i+1][k+1][1]+dp[i][k][1])%MOD;
continue;
}
if((i+1)==f)
{
dp[i+1][k+1][0]=(dp[i+1][k+1][0]+dp[i][k][0])%MOD;
dp[i+1][k+1][2]=(dp[i+1][k+1][2]+dp[i][k][2])%MOD;
continue;
}
if((i+1)<f && (i+1)<s)
{
dp[i+1][k+1][0]=(dp[i+1][k+1][0]+dp[i][k][0]*(k+1))%MOD;
dp[i+1][k+1][1]=(dp[i+1][k+1][1]+dp[i][k][1]*k)%MOD;
dp[i+1][k+1][2]=(dp[i+1][k+1][2]+dp[i][k][2]*k)%MOD;
dp[i+1][k+1][3]=(dp[i+1][k+1][3]+dp[i][k][3]*(k-1))%MOD;
continue;
}
if((i+1)>f && (i+1)>s)
{
dp[i+1][k+1][0]=(dp[i+1][k+1][0]+dp[i][k][0]*(k-1))%MOD;
dp[i+1][k+1][1]=(dp[i+1][k+1][1]+dp[i][k][1]*(k-1))%MOD;
dp[i+1][k+1][2]=(dp[i+1][k+1][2]+dp[i][k][2]*(k-1))%MOD;
dp[i+1][k+1][3]=(dp[i+1][k+1][3]+dp[i][k][3]*(k-1))%MOD;
continue;
}
if(s<(i+1) && (i+1)<f)
{
dp[i+1][k+1][0]=(dp[i+1][k+1][0]+dp[i][k][0]*k)%MOD;
dp[i+1][k+1][1]=(dp[i+1][k+1][1]+dp[i][k][1]*(k-1))%MOD;
dp[i+1][k+1][2]=(dp[i+1][k+1][2]+dp[i][k][2]*k)%MOD;
dp[i+1][k+1][3]=(dp[i+1][k+1][3]+dp[i][k][3]*(k-1))%MOD;
continue;
}
if(f<(i+1) && (i+1)<s)
{
dp[i+1][k+1][0]=(dp[i+1][k+1][0]+dp[i][k][0]*k)%MOD;
dp[i+1][k+1][1]=(dp[i+1][k+1][1]+dp[i][k][1]*k)%MOD;
dp[i+1][k+1][2]=(dp[i+1][k+1][2]+dp[i][k][2]*(k-1))%MOD;
dp[i+1][k+1][3]=(dp[i+1][k+1][3]+dp[i][k][3]*(k-1))%MOD;
continue;
}
}
}
cout<<(dp[n][1][0]+dp[n][1][1]+dp[n][1][2]+dp[n][1][3])%MOD<<"\n";
return 0;
}
