/// designed by Oruc Cabbarli
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define vi vector<int>
#define pii pair<int,int>
#define vpii vector<pii>
#define fi first
#define se second
#define pb push_back
#define all(v) v.begin(), v.end()
#define endl '\n'
template<typename T>void show(vector<T> &v){
for(auto &i: v){
cout << i << ' ';
}
cout << endl;
}
const int N = 1e5+5;
const int INF = 1e18;
const int LOG = 20;
const int MOD = 1e9+7;
int n,cs,cf,sum=0;
void dfs(int mask, int cur, int d){
if(mask == (1 << n) - 1){
if(cur == cf) sum = (sum+1)%MOD;
return;
}
for(int i = 1; i <= n; i++){
if(mask & (1 << (i-1))) continue;
if(d == 0 && i >= cur) continue;
if(d == 1 && i <= cur) continue;
dfs(mask | (1 << (i-1)), i, 1-d);
}
}
void solve(){
cin >> n >> cs >> cf;
if(cs > 1){
dfs(1 << (cs-1), cs, 0);
}
if(cs < n){
dfs(1 << (cs-1), cs, 1);
}
cout << sum << endl;
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
int t = 1;
//cin >> t;
for(int i = 1; i <= t; i++){
//cout << "Case #" << i << ": ";
solve();
}
}
