#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define ll long long
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define pb push_back
#define max_rng *max_element
#define min_rng *min_element
#define rep(i, n) for(int i = 1, _n = (n); i <= _n; ++i)
#define forn(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define ford(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)
template <class X, class Y>
inline bool maximize(X &x, Y y) {
return (x < y ? x = y, true : false);
}
template <class X, class Y>
inline bool minimize(X &x, Y y) {
return (x > y ? x = y, true : false);
}
template <class X>
inline void compress(vector<X> &a) {
sort(all(a));
a.resize(unique(all(a)) - a.begin());
}
int ctz(ll x) { return __builtin_ctzll(x); }
int lg(ll x) { return 63 - __builtin_clzll(x); }
int popcount(ll x) { return __builtin_popcount(x); }
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) {
return l + abs((ll) rng()) % (r - l + 1);
}
const ll oo = (ll) 1e17;
const int inf = (ll) 2e9 + 7, mod = (ll) 1e9 + 7;
const int mxn = 2e3 + 5, mxm = 1e3;
const int LG = 18, BASE = 311;
void sub(int &x, int y) { x -= y; if (x < 0) x += mod; }
void add(int &x, int y) { x += y; if (x >= mod) x -= mod; }
int n, cs, cf;
int f[mxn][mxn];
int main(void) {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
#define TASK "task"
if (fopen(TASK".inp", "r")) {
freopen(TASK".inp", "r", stdin);
freopen(TASK".out", "w", stdout);
}
cin >> n >> cs >> cf;
if (n == 2) return cout << 1, 0;
f[1][1] = 1;
forn(i, 1, n-1) forn(cc, 1, n) if (f[i][cc]) {
if (i+1 == cs || i+1 == cf) {
//create
add(f[i+1][cc+1], f[i][cc]);
// appends
add(f[i+1][cc], f[i][cc]);
}
else {
// merge
add(f[i+1][cc-1], 1LL * (cc - 1) * f[i][cc] % mod);
// create
add(f[i+1][cc+1], 1LL * (cc + 1 - (cf < i + 1) - (cs < i + 1)) * f[i][cc] % mod);
}
}
cout << f[n][1];
return 0;
}
