#include <bits/stdc++.h>
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
*/
using namespace std;
// using namespace __gnu_pbds;
using namespace chrono;
// mt19937 rng((int) std::chrono::steady_clock::now().time_since_epoch().count());
/*
template <class T> using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
*/
//***************** CONSTANTS *****************
const int MOD = 1'000'000'007;
//***************** GLOBAL VARIABLES *****************
int64_t dp[2001][2001];
//***************** AUXILIARY STRUCTS *****************
//***************** MAIN BODY *****************
void solve(){
int N, s, e;
cin >> N >> s >> e;
dp[1][1] = 1;
for(int i = 2; i <= N; i++)
for(int j = 1; j <= N; j++){
if(i == s || i == e){
dp[i][j] = (dp[i-1][j-1] + dp[i-1][j]) % MOD;
continue;
}
dp[i][j] = ((dp[i-1][j+1] * 1LL * j) % MOD + (dp[i-1][j-1] * 1LL *(j - (i > s) - (i > e))) % MOD) % MOD;
}
cout << dp[N][1] << '\n';
}
//***************** *****************
int32_t main(){
ios_base::sync_with_stdio(NULL);
cin.tie(NULL);
#ifdef LOCAL
auto begin = high_resolution_clock::now();
#endif
int tc = 1;
// cin >> tc;
for (int t = 0; t < tc; t++)
solve();
#ifdef LOCAL
auto end = high_resolution_clock::now();
cout << fixed << setprecision(4);
cout << "Execution Time: " << duration_cast<duration<double>>(end - begin).count() << "seconds" << endl;
#endif
return 0;
}
/*
If code gives a WA, check for the following :
1. I/O format
2. Are you clearing all global variables in between tests if multitests are a thing
3. Can you definitively prove the logic
*/
