#include<bits/stdc++.h>
using namespace std;
#define NAME ""
#define ll long long
#define pii pair < int , int >
#define fi first
#define se second
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i ++)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; i --)
#define REP(i, n) for (int i = 0, _n = (n); i < _n; i ++)
#define bit(x, i) (((x) >> (i)) & 1ll)
#define mask(x) (1ll << (x))
#define mem(f, x) memset(f, x, sizeof(f))
#define sz(x) (int32_t) (x.size())
const int nmax = 2000;
const int mod = 1e9 + 7;
int dp[nmax + 7][nmax + 7];
void add(int &x, int y) {
x += y;
if (x >= mod) {
x -= mod;
}
}
signed main() {
for(string s: {NAME, ""}) {
if (fopen((s + ".inp").c_str(), "r")) {
freopen((s + ".inp").c_str(), "r", stdin);
freopen((s + ".out").c_str(), "w", stdout);
break;
}
}
cin.tie(0)->sync_with_stdio(0);
int n, cs, cf;
cin >> n >> cs >> cf;
dp[1][1] = 1;
FOR(i, 2, n) {
FOR(j, 1, i) {
dp[i % 2][j] = 0;
}
FOR(j, 1, i - 1) {
add(dp[i % 2][j + 1], dp[1 - i % 2][j]);
if (i == cs || i == cf) {
add(dp[i % 2][j], dp[1 - i % 2][j]);
}
else if (j - 1 > 0) {
add(dp[i % 2][j - 1], dp[1 - i % 2][j]);
}
}
// cout << i << ":\n";
// FOR(j, 1, i) {
// cout << j << " " << dp[i % 2][j] << "\n";
// }
}
cout << dp[n % 2][1];
return 0;
}
