#include <bits/stdc++.h>
#ifdef GUDEB
#define D(x) cerr << #x << ": " << (x) << '\n';
#define ifdeb if(true)
#else
#define D(x) ;
#define ifdeb if(false)
#endif
#define all(x) begin(x), end(x)
using namespace std;
using ull = unsigned long long;
using ll = long long;
// #define int ll;
constexpr ll mod = 1000000007;
ll dp1[2002][2002];
ll dp2[2002][2002];
void solve() {
int n, S, F;
cin >> n >> S >> F;
--S; --F;
ll (*dp)[2002] = dp1;
ll (*ndp)[2002] = dp2;
if(F >= n/2) {
F = n-F-1;
S = n-S-1;
}
dp[F][S] = 1;
dp[n-F-1][n-S-1] = 1;
for(int i = n-1; i >= 1; --i) {
for(int f = 0; f < i; ++f) {
if(f-1 > F && f+1 < i-F) continue;
if(f < F-(n-1-i) || f > n-1-F) continue;
ll d = 0;
for(int s = 0; s <= f; ++s) {
d += dp[f+1][s];
d %= mod;
ndp[i-1-f][i-1-s] = d;
}
for(int s = f+1; s < i; ++s) {
d += dp[f][s];
d %= mod;
ndp[i-1-f][i-1-s] = d;
}
}
swap(dp, ndp);
// cerr << "i " << i << '\n';
// for(int f = 0; f < i; ++f) {
// for(int s = 0; s < i; ++s) {
// cerr << dp[f][s] << ' ';
// }
// cerr << '\n';
// }
}
cout << dp[0][0] << '\n';
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout << setprecision(20);
solve();
}
