#include <bits/stdc++.h>
//#pragma GCC optimize ("03")
#define FastIO ios_base::sync_with_stdio(false) , cin.tie(0) , cout.tie(0)
#define FILES freopen("kangaroo.in" , "r" , stdin) , freopen("kangaroo.out" , "w" , stdout)
#define ll long long
#define ull unsigned long long
#define ld long double
#define eb emplace_back
#define pb push_back
#define qwerty1 first
#define qwerty2 second
#define qwerty3 -> first
#define qwerty4 -> second
#define umap unordered_map
#define uset unordered_set
#define pii pair < ll , ll >
#define pq priority_queue
#define dbg(x) cerr << #x << ": " << x << '\n'
namespace FastRead
{
char __buff[5000];ll __lg = 0 , __p = 0;
char nc()
{
if(__lg == __p){__lg = fread(__buff , 1 , 5000 , stdin);__p = 0;if(!__lg) return EOF;}
return __buff[__p++];
}
template<class T>void read(T&__x)
{
T __sgn = 1; char __c;while(!isdigit(__c = nc()))if(__c == '-')__sgn = -1;
__x = __c - '0';while(isdigit(__c = nc()))__x = __x * 10 + __c - '0';__x *= __sgn;
}
}
using namespace FastRead;
using namespace std;
const ll N = 2e3 + 10;
const ll M = 1e9 + 7;
const ld PI = acos(-1);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll n , cs , cf;
ll dp[N][N][4];
void add(ll &x , ll y)
{
y %= M;
x += y;
x %= M;
}
signed main()
{
//#ifndef ONLINE_JUDGE
//FastIO , FILES;
//#endif
ll i , j;
cin >> n >> cs >> cf;
dp[1][1][0] = 1;
for(i = 2 ; i <= n ; i++)
for(j = 1 ; j <= i ; j++)
{
if(i != cf && i != cs)
{
add(dp[i][j][0] , j * dp[i - 1][j + 1][0] % M);
add(dp[i][j][1] , j * dp[i - 1][j + 1][1] % M);
add(dp[i][j][2] , j * dp[i - 1][j + 1][2] % M);
add(dp[i][j][3] , j * dp[i - 1][j + 1][3] % M);
}
if(i == cs)
{
add(dp[i][j][1] , dp[i - 1][j][0]);
add(dp[i][j][3] , dp[i - 1][j][2]);
}
else if(i == cf)
{
add(dp[i][j][2] , dp[i - 1][j][0]);
add(dp[i][j][3] , dp[i - 1][j][1]);
}
else
{
;
}
if(i == cs)
{
add(dp[i][j][0] , dp[i - 1][j - 1][0]);
add(dp[i][j][0] , dp[i - 1][j - 1][1]);
add(dp[i][j][2] , dp[i - 1][j - 1][2]);
add(dp[i][j][2] , dp[i - 1][j - 1][3]);
}
else if(i == cf)
{
add(dp[i][j][0] , dp[i - 1][j - 1][0]);
add(dp[i][j][0] , dp[i - 1][j - 1][2]);
add(dp[i][j][1] , dp[i - 1][j - 1][1]);
add(dp[i][j][1] , dp[i - 1][j - 1][3]);
}
else
{
if(j > 2)
{
add(dp[i][j][0] , (j - 2) * dp[i - 1][j - 1][0]);
add(dp[i][j][1] , (j - 2) * dp[i - 1][j - 1][1]);
add(dp[i][j][2] , (j - 2) * dp[i - 1][j - 1][2]);
add(dp[i][j][3] , (j - 2) * dp[i - 1][j - 1][3]);
}
if(i < cs)
{
add(dp[i][j][0] , dp[i - 1][j - 1][0]);
add(dp[i][j][0] , dp[i - 1][j - 1][1]);
add(dp[i][j][2] , dp[i - 1][j - 1][2]);
add(dp[i][j][2] , dp[i - 1][j - 1][3]);
}
if(i < cf)
{
add(dp[i][j][0] , dp[i - 1][j - 1][0]);
add(dp[i][j][0] , dp[i - 1][j - 1][2]);
add(dp[i][j][1] , dp[i - 1][j - 1][1]);
add(dp[i][j][1] , dp[i - 1][j - 1][3]);
}
}
}
ll ans = 0;
for(i = 0 ; i < 4 ; i++)
add(ans , dp[n][1][i]);
cout << ans;
return 0;
}
