#include <bits/stdc++.h>
using namespace std;
using LL=long long;
#define FOR(i,l,r) for(int i=(l);i<=(r);++i)
#define REP(i,n) FOR(i,0,(n)-1)
#define ssize(x) int(x.size())
template<class A,class B>auto&operator<<(ostream&o,pair<A,B>p){return o<<'('<<p.first<<", "<<p.second<<')';}
template<class T>auto operator<<(ostream&o,T x)->decltype(x.end(),o){o<<'{';int i=0;for(auto e:x)o<<(", ")+2*!i++<<e;return o<<'}';}
#ifdef DEBUG
#define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...);}(x),cerr<<'\n'
#else
#define debug(...) {}
#endif
int main() {
cin.tie(0)->sync_with_stdio(0);
const long long mod = 1e9 + 7;
int n, cs, cf;
cin >> n >> cs >> cf;
debug(n, cs, cf);
if (cs > cf) {
swap(cs, cf);
}
debug(cs, cf);
vector <vector <long long> >dp(n + 1, vector <long long> (n + 1, 0ll));
dp[1][1] = 1;
FOR(i, 1, n - 1) {
FOR(j, 1, n - 1) {
if (i + 1 == cs || i + 1 == cf) {
dp[i + 1][j + 1] = (dp[i + 1][j + 1] + dp[i][j]) % mod;
dp[i + 1][j] = (dp[i + 1][j] + dp[i][j]) % mod;
}
else if (i < cs) {
dp[i + 1][j + 1] = (dp[i + 1][j + 1] + dp[i][j] * (j + 1)) % mod;
dp[i + 1][j - 1] = (dp[i + 1][j - 1] + dp[i][j] * (j - 1)) % mod;
}
else if (i < cf) {
dp[i + 1][j + 1] = (dp[i + 1][j + 1] + dp[i][j] * j) % mod;
dp[i + 1][j - 1] = (dp[i + 1][j - 1] + dp[i][j] * (j - 1)) % mod;
}
else { // i >= cf
dp[i + 1][j + 1] = (dp[i + 1][j + 1] + dp[i][j] * (j - 1)) % mod;
dp[i + 1][j - 1] = (dp[i + 1][j - 1] + dp[i][j] * (j - 1)) % mod;
}
}
}
debug(dp);
cout << dp[n][1] << endl;
}
