#include <bits/stdc++.h>
// #pragma GCC optimize("Ofast,no-stack-protector,unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
// #define int long long
#define ll long long
#define pii pair<int, int>
#define all(v) v.begin(), v.end()
using namespace std;
const int oo = 1e9 + 9;
const int MAX = 40 + 5, LOGMAX = 20, B = 441, MOD = 1e9 + 7;
int n, cs, cf;
int dp[MAX][MAX][MAX][3];
int rec(int i, int prev, int finpos, int dir){
if(i == n - 1) return (finpos == dir + 1);
if(dp[i][prev][finpos][dir] != -1) return dp[i][prev][finpos][dir];
int ans = 0;
if(dir == 2 || dir == 0){
for(int k = 1; k < prev; k++){
if(k == finpos) continue;
ans += rec(i + 1, k, finpos - (prev < finpos), 1);
ans %= MOD;
}
}
if(dir == 2 || dir == 1){
for(int k = prev + 1; k <= n - i + 1; k++){
if(k == finpos) continue;
ans += rec(i + 1, k - 1, finpos - (prev < finpos), 0);
ans %= MOD;
}
}
return dp[i][prev][finpos][dir] = ans;
}
void solve(){
cin >> n >> cs >> cf;
memset(dp, -1, sizeof(dp));
int ans = rec(1, cs, cf, 2);
cout << ans << '\n';
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
while(t--) solve();
}
