//Author RufatM
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<string> vs;
#define fastio ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define endl '\n'
#define pb push_back
#define pf push_front
#define eb emplace_back
#define ff first
#define ss second
#define all(x) begin(x),end(x)
#define rall(x) rbegin(x),rend(x)
#define mt19937_64 mt_rand(chrono::steady_clock::now().time_since_epoch().count())
#define ordered_set tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>
const int MOD=1000000007;
const int INF=1000000007;
const ll LINF=4e18;
const int MAXN=100005;
ll n,cs,cf;
ll ans = 0;
bool used[50];
void dfs(int cur,int prev,int vis){
if(vis == n){
if(cur == cf){
ans = (ans+1)%MOD;
}
return;
}
if(prev == -1){
for(int nxt=1;nxt<=n;nxt++){
if(nxt==cs){
continue;
}
if(used[nxt]){
continue;
}
used[nxt] = true;
dfs(nxt,cur,vis+1);
used[nxt] = false;
}
}
else{
if(prev<cur){
for(int nxt=1;nxt<cur;nxt++){
if(used[nxt]){
continue;
}
used[nxt] = true;
dfs(nxt,cur,vis+1);
used[nxt] = false;
}
}
else{
for(int nxt=cur+1;nxt<=n;nxt++){
if(used[nxt]){
continue;
}
used[nxt] = true;
dfs(nxt,cur,vis+1);
used[nxt] = false;
}
}
}
}
signed main(){
fastio;
#ifndef ONLINE_JUDGE
//freopen("input.txt","r",stdin);
//freopen("output.txt","w",stdout);
#endif
int t=1;
//cin >> t;
while(t--){
cin >> n >> cs >> cf;
memset(used,false,sizeof(used));
used[cs] = true;
dfs(cs,-1,1);
cout << ans << endl;
}
}
