#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")

////////////////////////////////////////////////////////////////////////////////
template <unsigned M_> struct ModInt {
  static constexpr unsigned M = M_;
  unsigned x;
  constexpr ModInt() : x(0U) {}
  constexpr ModInt(unsigned x_) : x(x_ % M) {}
  constexpr ModInt(unsigned long long x_) : x(x_ % M) {}
  constexpr ModInt(int x_) : x(((x_ %= static_cast<int>(M)) < 0) ? (x_ + static_cast<int>(M)) : x_) {}
  constexpr ModInt(long long x_) : x(((x_ %= static_cast<long long>(M)) < 0) ? (x_ + static_cast<long long>(M)) : x_) {}
  ModInt &operator+=(const ModInt &a) { x = ((x += a.x) >= M) ? (x - M) : x; return *this; }
  ModInt &operator-=(const ModInt &a) { x = ((x -= a.x) >= M) ? (x + M) : x; return *this; }
  ModInt &operator*=(const ModInt &a) { x = (static_cast<unsigned long long>(x) * a.x) % M; return *this; }
  ModInt &operator/=(const ModInt &a) { return (*this *= a.inv()); }
  ModInt pow(long long e) const {
    if (e < 0) return inv().pow(-e);
    ModInt a = *this, b = 1U; for (; e; e >>= 1) { if (e & 1) b *= a; a *= a; } return b;
  }
  ModInt inv() const {
    unsigned a = M, b = x; int y = 0, z = 1;
    for (; b; ) { const unsigned q = a / b; const unsigned c = a - q * b; a = b; b = c; const int w = y - static_cast<int>(q) * z; y = z; z = w; }
    assert(a == 1U); return ModInt(y);
  }
  ModInt operator+() const { return *this; }
  ModInt operator-() const { ModInt a; a.x = x ? (M - x) : 0U; return a; }
  ModInt operator+(const ModInt &a) const { return (ModInt(*this) += a); }
  ModInt operator-(const ModInt &a) const { return (ModInt(*this) -= a); }
  ModInt operator*(const ModInt &a) const { return (ModInt(*this) *= a); }
  ModInt operator/(const ModInt &a) const { return (ModInt(*this) /= a); }
  template <class T> friend ModInt operator+(T a, const ModInt &b) { return (ModInt(a) += b); }
  template <class T> friend ModInt operator-(T a, const ModInt &b) { return (ModInt(a) -= b); }
  template <class T> friend ModInt operator*(T a, const ModInt &b) { return (ModInt(a) *= b); }
  template <class T> friend ModInt operator/(T a, const ModInt &b) { return (ModInt(a) /= b); }
  explicit operator bool() const { return x; }
  bool operator==(const ModInt &a) const { return (x == a.x); }
  bool operator!=(const ModInt &a) const { return (x != a.x); }
  friend std::ostream &operator<<(std::ostream &os, const ModInt &a) { return os << a.x; }
};
////////////////////////////////////////////////////////////////////////////////

constexpr unsigned MO = 1000000007;
using Mint = ModInt<MO>;


/*
  DP determining small/large and relative position
  0: small
  1: large
  010 -> 0
  11 -> impossible
  100... -> left end fixed
  ...001 -> right end fixed
*/
Mint solve(int N, int A, int B) {
  // [k]: k 0's
  vector<Mint> crt{1};
  for (int x = 0; x < N; ++x) {
    const int len = crt.size();
    vector<Mint> nxt(len + 1, 0);
    if (x == A || x == B) {
      for (int k = 0; k < len; ++k) {
        // 0
        nxt[k + 1] += crt[k];
        // 1
        if (k) nxt[k] += crt[k];
      }
    } else {
      // # of fixed ends
      const int s = ((A < x) ? 1 : 0) + ((B < x) ? 1 : 0);
      for (int k = 0; k < len; ++k) {
        // 0
        nxt[k + 1] += crt[k] * (k + 1 - s);
        // 1
        if (k) nxt[k - 1] += crt[k] * (k - 1);
      }
    }
    crt.swap(nxt);
  }
  return crt[1];
}

int main() {
#ifdef LOCAL
  for (int n = 2; n <= 10; ++n) {
    vector<vector<int>> freq(n, vector<int>(n, 0));
    vector<int> ps(n);
    for (int i = 0; i < n; ++i) ps[i] = i;
    do {
      bool ok = true;
      for (int i = 1; i < n - 1; ++i) ok = ok && ((ps[i - 1] > ps[i]) != (ps[i] > ps[i + 1]));
      if (ok) {
        ++freq[ps[0]][ps[n - 1]];
      }
    } while (next_permutation(ps.begin(), ps.end()));
    cerr << "n = " << n << endl;
    for (int a = 0; a < n; ++a) {
      cerr << freq[a] << endl;
    }
    for (int a = 0; a < n; ++a) for (int b = 0; b < n; ++b) if (a != b) {
      assert(Mint(freq[a][b]) == solve(n, a, b));
    }
  }
#endif
  
  int N, A, B;
  for (; ~scanf("%d%d%d", &N, &A, &B); ) {
    --A;
    --B;
    const Mint ans = solve(N, A, B);
    printf("%u\n", ans.x);
  }
  return 0;
}