#include<bits/stdc++.h>
using namespace std;
void dbg_out() { cout << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cout << ' ' << H; dbg_out(T...); }
#ifdef LOCAL
#define debug(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define debug(...) "zzz"
#endif
using ll = long long;
using ld = long double;
using pii = pair<ll,ll>;
#define FOR(i, n) for(int i = 1; i<=n; i++)
#define F0R(i, n) for(int i = 0; i<n; i++)
#define all(x) x.begin(), x.end()
#define mp make_pair
#define pb push_back
#define f first
#define s second
template<typename T, typename = void> struct is_iterable : false_type {};
template<typename T> struct is_iterable<T, void_t<decltype(begin(declval<T>())),decltype(end(declval<T>()))>> : true_type {};
template<typename T> typename enable_if<is_iterable<T>::value&&!is_same<T, string>::value,ostream&>::type operator<<(ostream &cout, T const &v);
template<typename A, typename B> ostream& operator<<(ostream &cout, pair<A, B> const &p) { return cout << "(" << p.f << ", " << p.s << ")"; }
template<typename T> typename enable_if<is_iterable<T>::value&&!is_same<T, string>::value,ostream&>::type operator<<(ostream &cout, T const &v) {
cout << "[";
for (auto it = v.begin(); it != v.end();) {
cout << *it;
if (++it != v.end()) cout << ", ";
}
return cout << "]";
}
//var
ll T;
const ll MOD = 1e9 + 7;
struct mint {
int x;
mint() : x(0) {}
template <class T> mint(T value) : x(value % MOD) { if (x < 0) x += MOD; }
mint & operator+=(const mint &oth) { x += oth.x; if (x >= MOD) x -= MOD; return *this; }
mint & operator-=(const mint &oth) { x -= oth.x; if (x < 0) x += MOD; return *this; }
mint & operator*=(const mint &oth) { x = (long long) x * oth.x % MOD; return *this; }
friend mint operator+(mint l, const mint &r) { return l += r; }
friend mint operator-(mint l, const mint &r) { return l -= r; }
friend mint operator*(mint l, const mint &r) { return l *= r; }
mint & operator--() { if (--x == -1) x = MOD - 1; return *this; }
mint & operator++() { if (++x == MOD) x = 0; return *this; }
mint operator--(int) { mint temp = *this; --*this; return temp; }
mint operator++(int) { mint temp = *this; ++*this; return temp; }
mint operator-() const { return 0 - *this; }
mint operator+() const { return *this; }
friend bool operator==(const mint &l, const mint &r) { return l.x == r.x; }
friend bool operator!=(const mint &l, const mint &r) { return l.x != r.x; }
friend ostream & operator<<(ostream &out, const mint &a) { return out << a.x; }
mint pow(long long e = MOD - 2) const {
mint ans = 1, b = *this;
while (e > 0) {
if (e % 2 == 1) {
ans *= b;
}
b *= b;
e /= 2;
}
return ans;
}
};
void solve() {
ll n, x, y;
cin >> n >> x >> y;
x--, y--;
vector<mint> dp(n + 1, 0);
dp[0] = 1;
ll seen_ends = 0;
F0R (i, n) {
vector<mint> new_dp(n + 1, 0);
for (int num_comps = 0; num_comps <= n; num_comps++) if (dp[num_comps] != 0) {
mint p = dp[num_comps];
if (i == x or i == y) {
if (num_comps != 0) new_dp[num_comps] += p;
new_dp[num_comps + 1] += p;
} else {
// individual options
{
ll num_options = num_comps + 1 - seen_ends;
new_dp[num_comps + 1] += p * num_options;
}
if (num_comps >= 2) {
// merge components
ll num_options = num_comps - 1;
new_dp[num_comps - 1] += p * num_options;
}
}
}
if (i == x) seen_ends++;
if (i == y) seen_ends++;
swap(dp, new_dp);
}
cout << dp[1] << "\n";
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
T = 1;
//cin >> T;
FOR(t, T)
solve();
cout.flush();
return 0;
}
