#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;
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) {
ll d = 0;
for(int s = 0; s < i; ++s) {
d += dp[f + (s <= f)][s];
d %= mod;
ndp[i-1-f][i-1-s] = d;
}
}
swap(dp, ndp);
}
cout << dp[0][0] << '\n';
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout << setprecision(20);
solve();
}
