#include <bits/stdc++.h>
using namespace std;
#define FOR(i, j, k) for(int i=(j); i<=(k); i++)
#define FFOR(i, j, k) for(int i=(j); i<(k); i++)
#define DFOR(i, j, k) for(int i=(j); i>=(k); i--)
#define bug(x) cerr<<#x<<" = "<<(x)<<'\n'
#define pb push_back
#define mp make_pair
#define bit(s, i) (((s)>>(i))&1LL)
#define mask(i) ((1LL<<(i)))
#define builtin_popcount __builtin_popcountll
#define __builtin_popcount __builtin_popcountll
using ll=long long; using ld=long double;
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); const ld pi=acos(0)*2;
template <typename T> inline void read(T &x){char c; bool nega=0; while((!isdigit(c=getchar()))&&(c!='-')); if(c=='-'){nega=1; c=getchar();} x=c-48; while(isdigit(c=getchar())) x=x*10+c-48; if(nega) x=-x;}
template <typename T> inline void writep(T x){if(x>9) writep(x/10); putchar(x%10+48);}
template <typename T> inline void write(T x){if(x<0){ putchar('-'); x=-x;} writep(x);}
template <typename T> inline void writeln(T x){write(x); putchar('\n');}
#define taskname "Kangaroo"
int n;
ll f[2002];
ll g[2002];
int s, e;
const ll base=1000000007;
int main(){
#ifdef Aria
if(fopen(taskname".in", "r"))
freopen(taskname".in", "r", stdin);
#endif // Aria
f[1]=1;
read(n);
read(s);
read(e);
DFOR(i, n-1, 1){
FOR(j, 1, n) g[j]=0;
if(i==s||i==e){
FOR(j, 1, n) if(f[j]) g[j]=(g[j]+f[j])%base;
FOR(j, 1, n) if(f[j]) g[j+1]=(g[j+1]+f[j])%base;
}
else{
FOR(j, 1, n) if(f[j]){
g[j-1]=(g[j-1]+f[j]*(j-1))%base;
g[j+1]=(g[j+1]+f[j]*(j-1))%base;
if(i>e) g[j+1]=(g[j+1]+f[j])%base;
if(i>s) g[j+1]=(g[j+1]+f[j])%base;
}
}
FOR(j, 1, n) f[j]=g[j];
// bug(i);
// FOR(i, 1, n) cerr<<f[i]<<" \n"[i==n];
}
writeln(f[1]);
}
