/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author
 */

#include <iostream>
#include <fstream>

#ifndef SOLUTION_COMMON_H

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using PI = pair<int, int>;
template<class T> using V = vector<T>;
using VI = V<int>;
#define _1 first
#define _2 second

#ifdef MY_DEBUG
# define DEBUG(x) x
#else
# define DEBUG(x)
#endif

template<class T>
inline void debug(T &A) {
  DEBUG(
      for (const auto &a : A) {
        cerr << a << " ";
      }
      cerr << '\n';
  )
}

template<class T, class Func>
inline void debug_with_format(T &A, Func f) {
  DEBUG(
      for (const auto &a : A) {
        cerr << f(a) << " ";
      }
      cerr << '\n';
  )
}

template<class T>
inline void debug_dim2(T &A) {
  DEBUG(
      for (const auto &as : A) {
        debug(as);
      }
  )
}

template<typename ... Args>
inline void debug(const char *format, Args const &... args) {
  DEBUG(
      fprintf(stderr, format, args ...);
      cerr << '\n';
  )
}

template<typename ... Args>
string format(const string &fmt, Args ... args) {
  size_t len = snprintf(nullptr, 0, fmt.c_str(), args ...);
  vector<char> buf(len + 1);
  snprintf(&buf[0], len + 1, fmt.c_str(), args ...);
  return string(&buf[0], &buf[0] + len);
}

template<class T1, class T2>
string fmtP(pair<T1, T2> a) {
  stringstream ss;
  ss << "(" << a._1 << "," << a._2 << ")";
  return ss.str();
}

#define SOLUTION_COMMON_H

#endif //SOLUTION_COMMON_H


class Comb {
public:
  int MOD;
  V<ll> F, I;

  Comb(int N, int MOD): MOD(MOD), F(N + 1), I(N + 1) {
    F[0] = 1;
    for (int i = 1; i <= N; ++i) {
      F[i] = F[i - 1] * i % MOD;
    }

    I[N] = pow_mod(F[N], MOD - 2, MOD);
    for (int i = N - 1; i >= 0; --i) {
      I[i] = I[i + 1] * (i + 1) % MOD;
    }
  }

  static ll pow_mod(ll x, int k, int MOD) {
    ll res = k >= 2 ? pow_mod(x * x % MOD, k / 2, MOD) : 1ll;
    if (k&1) res = res * x % MOD;
    return res;
  };

  ll operator()(int n, int k) {
    if (k < 0 || k > n) return 0ll;
    return F[n] * I[n - k] % MOD * I[k] % MOD;
  };

  ll rev(int x) {
    return F[x - 1] * I[x] % MOD;
  }
};

const int MOD = 1000000007;

inline void add(ll &a, ll b) {
  a += b;
  if (a >= MOD) a -= MOD;
}

inline void mul(ll &a, ll b) {
  a = a * b % MOD;
}

class B {
public:
  void solve(std::istream& in, std::ostream& out) {
    int N, K;
    in >> N >> K;
    Comb comb(N + 1, MOD);
    ll ALL = comb.F[N];
    comb(ALL, comb.I[K]);

    debug("ALL:%d", ALL);

    ll ans = 0ll;
    for (int i = 1; i <= N; ++i) {
      // i, i+1 どちらもあるケース
      ll a = 0ll;
      if (N != i) {
        a = comb(N - 2, K - 2);
        mul(a, comb.F[K]);
        mul(a, comb.rev(2));
      }

      // iがないケース
      ll b = 0ll;
      if (N - 1 - K >= 0) {
        b = comb.F[N - 1];
        mul(b, comb.I[max(0, N - 1 - K)]);
      }

      debug("i:%d a:%d b:%d", i, a, b);

      add(a, b);
      mul(a, i);
      add(ans, a);
    }

    out << ans;
  }
};


int main() {
	B solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	solver.solve(in, out);
	return 0;
}