#include <bits/stdc++.h>
#include <cassert>
typedef long long int ll;
using namespace std;

// @@ !! LIM(mod debug cmpNaive)
// --> f:gcd mod f:<< debug cmpNaive
// ---- inserted function gcd from util.cc
// g = eGCD(a, b, s, t)  --->  sa + tb = g
ll eGCD(ll a, ll b, ll& s, ll& t) {
  if (a == 0) {
    s = 0;
    t = 1;
    return b;
  }
  ll u = 0;
  ll g = eGCD(b % a, a, t, u);
  s = u - (b / a) * t;
  return g;
}

// gcd(0, x) = x, gcd(-x, y) = gcd(x, y)
ll gcd(ll a, ll b) {
  ll dummy1 = 0;
  ll dummy2 = 0;
  return eGCD(abs(a), abs(b), dummy1, dummy2);
}
// ---- end gcd
// ---- inserted library file mod.cc

ll MOD = 1e9 + 7;
// ll MOD = 998244353;

struct Fp {
  ll val;

  ll _calc_from_ll(ll t = 0) {
    if      (t >= MOD)  return t % MOD;
    else if (t >= 0)    return t;
    else if (t >= -MOD) return t + MOD;
    else {
      ll v = t % MOD;
      if (v == 0) return 0;
      else        return v + MOD;
    }
  }

  Fp(ll t = 0) : val(_calc_from_ll(t)) {}
  Fp(const Fp& t) : val(t.val) {}
  Fp& operator =(const Fp& t) { val = t.val; return *this; }
  Fp& operator =(ll t) { val = _calc_from_ll(t); return *this; }
  Fp& operator =(int t) { val = _calc_from_ll(t); return *this; }

  Fp& operator +=(const Fp& t) {
    val += t.val;
    if (val >= MOD) val -= MOD;
    return *this;
  }

  Fp& operator -=(const Fp& t) {
    val -= t.val;
    if (val < 0) val += MOD;
    return *this;
  }

  Fp& operator *=(const Fp& t) {
    val = (val * t.val) % MOD;
    return *this;
  }

  Fp inv() const {
    if (val == 0) {
      cerr << "inv() is called for zero." << endl;
      exit(1);
    }
    ll u = 0;
    ll v = 0;
    eGCD(val, MOD, u, v);
    return Fp(u);
  }

  Fp& operator /=(const Fp& t) {
    return (*this) *= t.inv();
  }

  Fp operator +(const Fp& t) const { return Fp(val) += t; }
  Fp operator -(const Fp& t) const { return Fp(val) -= t; }
  Fp operator *(const Fp& t) const { return Fp(val) *= t; }
  Fp operator /(const Fp& t) const { return Fp(val) /= t; }
  Fp operator -() const { return Fp(-val); }

  bool operator ==(const Fp& t) const { return val == t.val; }
  bool operator !=(const Fp& t) const { return val != t.val; }
  
  operator ll() const { return val; }

};

Fp operator +(int x, const Fp& y) { return Fp(x) + y; }
Fp operator -(int x, const Fp& y) { return Fp(x) - y; }
Fp operator *(int x, const Fp& y) { return Fp(x) * y; }
Fp operator /(int x, const Fp& y) { return Fp(x) / y; }
Fp operator +(ll x, const Fp& y) { return Fp(x) + y; }
Fp operator -(ll x, const Fp& y) { return Fp(x) - y; }
Fp operator *(ll x, const Fp& y) { return Fp(x) * y; }
Fp operator /(ll x, const Fp& y) { return Fp(x) / y; }
Fp operator +(const Fp& x, int y) { return x + Fp(y); }
Fp operator -(const Fp& x, int y) { return x - Fp(y); }
Fp operator *(const Fp& x, int y) { return x * Fp(y); }
Fp operator /(const Fp& x, int y) { return x / Fp(y); }
Fp operator +(const Fp& x, ll y) { return x + Fp(y); }
Fp operator -(const Fp& x, ll y) { return x - Fp(y); }
Fp operator *(const Fp& x, ll y) { return x * Fp(y); }
Fp operator /(const Fp& x, ll y) { return x / Fp(y); }

istream& operator>> (istream& is, Fp& t) {
  ll x; is >> x;
  t = x;
  return is;
}

ostream& operator<< (ostream& os, const Fp& t) {
  os << t.val;
  return os;
}

class Comb {
  int nMax;
  vector<Fp> vFact;
  vector<Fp> vInvFact;
public:
  Comb(int nm) : nMax(nm), vFact(nm+1), vInvFact(nm+1) {
    vFact.at(0) = 1;
    for (int i = 1; i <= nMax; i++) vFact.at(i) = i * vFact.at(i-1);
    vInvFact.at(nMax) = vFact.at(nMax).inv();
    for (int i = nMax; i >= 1; i--) vInvFact.at(i-1) = i * vInvFact.at(i);
  }
  Fp fact(int n) { return vFact.at(n); }
  Fp comb(int n, int r) {
    return vFact.at(n) * vInvFact.at(r) * vInvFact.at(n-r);
  }
  // The number of permutation extracting r from n.
  Fp perm(int n, int r) {
    return vFact.at(n) * vInvFact.at(n-r);
  }
};

// ---- end mod.cc
// ---- inserted function << from util.cc
template <typename T1, typename T2>
ostream& operator<< (ostream& os, const pair<T1,T2>& p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}

template <typename T1, typename T2, typename T3>
ostream& operator<< (ostream& os, const tuple<T1,T2,T3>& t) {
  os << "(" << get<0>(t) << ", " << get<1>(t)
     << ", " << get<2>(t) << ")";
  return os;
}

template <typename T1, typename T2, typename T3, typename T4>
ostream& operator<< (ostream& os, const tuple<T1,T2,T3,T4>& t) {
  os << "(" << get<0>(t) << ", " << get<1>(t)
     << ", " << get<2>(t) << ", " << get<3>(t) << ")";
  return os;
}

template <typename T>
ostream& operator<< (ostream& os, const vector<T>& v) {
  os << '[';
  for (auto it = v.begin(); it != v.end(); it++) {
    if (it != v.begin()) os << ", ";
    os << *it;
  }
  os << ']';

  return os;
}

template <typename T>
ostream& operator<< (ostream& os, const set<T>& v) {
  os << '{';
  for (auto it = v.begin(); it != v.end(); it++) {
    if (it != v.begin()) os << ", ";
    os << *it;
  }
  os << '}';

  return os;
}

template <typename T>
ostream& operator<< (ostream& os, const multiset<T>& v) {
  os << '{';
  for (auto it = v.begin(); it != v.end(); it++) {
    if (it != v.begin()) os << ", ";
    os << *it;
  }
  os << '}';

  return os;
}

template <typename T1, typename T2>
ostream& operator<< (ostream& os, const map<T1, T2>& mp) {
  os << '[';
  for (auto it = mp.begin(); it != mp.end(); it++) {
    if (it != mp.begin()) os << ", ";
    os << it->first << ": " << it->second;
  }
  os << ']';

  return os;
}

template <typename T, typename T2>
ostream& operator<< (ostream& os, const queue<T, T2>& orig) {
  queue<T, T2> que(orig);
  bool first = true;
  os << '[';
  while (!que.empty()) {
    T x = que.front(); que.pop();
    if (!first) os << ", ";
    os << x;
    first = false;
  }
  return os << ']';
}

template <typename T, typename T2, typename T3>
ostream& operator<< (ostream& os, const priority_queue<T, T2, T3>& orig) {
  priority_queue<T, T2, T3> pq(orig);
  bool first = true;
  os << '[';
  while (!pq.empty()) {
    T x = pq.top(); pq.pop();
    if (!first) os << ", ";
    os << x;
    first = false;
  }
  return os << ']';
}

template <typename T>
ostream& operator<< (ostream& os, const stack<T>& st) {
  stack<T> tmp(st);
  os << '[';
  bool first = true;
  while (!tmp.empty()) {
    T& t = tmp.top();
    if (first) first = false;
    else os << ", ";
    os << t;
    tmp.pop();
  }
  os << ']';
  return os;
}

#if __cplusplus >= 201703L
template <typename T>
ostream& operator<< (ostream& os, const optional<T>& t) {
  if (t.has_value()) os << "v(" << t.value() << ")";
  else               os << "nullopt";
  return os;
}
#endif

// ---- end <<
// ---- inserted library file debug.cc
template <class... Args>
string dbgFormat(const char* fmt, Args... args) {
  size_t len = snprintf(nullptr, 0, fmt, args...);
  char buf[len + 1];
  snprintf(buf, len + 1, fmt, args...);
  return string(buf);
}

template <class Head>
void dbgLog(Head&& head) {
  cerr << head << endl;
}

template <class Head, class... Tail>
void dbgLog(Head&& head, Tail&&... tail)
{
  cerr << head << " ";
  dbgLog(forward<Tail>(tail)...);
}

#if DEBUG
  #define DLOG(...)        dbgLog(__VA_ARGS__)
  #define DFMT(...)        cerr << dbgFormat(__VA_ARGS__) << endl
  #define DCALL(func, ...) func(__VA_ARGS__)
#else
  #define DLOG(...)
  #define DFMT(...)
  #define DCALL(func, ...)
#endif

// ---- end debug.cc
// ---- inserted library file cmpNaive.cc

const string end_mark("^__=end=__^");
const string end_file_mark("^__=end_file=__^");

int naive(istream& cin, ostream& cout);
int body(istream& cin, ostream& cout);

void cmpNaive() {
  while (true) {
    string s;
    getline(cin, s);
    bool run_body;
    if (s.at(0) == 'Q') {
      return;
    }else if (s.at(0) == 'B') {
      run_body = true;
    }else if (s.at(0) == 'N') {
      run_body = false;
    }else {
      cerr << "Unknown body/naive specifier.\n";
      exit(1);
    }
    string input_s;
    while (true) {
      getline(cin, s);
      if (s == end_mark) break;
      input_s += s;
      input_s += "\n";
    }
    stringstream ss_in(move(input_s));
    stringstream ss_out;
    if (run_body) {
      body(ss_in, ss_out);
    }else {
      naive(ss_in, ss_out);
    }
    cout << ss_out.str() << end_mark << endl;
  }
}

int main(int argc, char *argv[]) {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout << setprecision(20);

#if CMPNAIVE
  if (argc == 2) {
    if (strcmp(argv[1], "cmpNaive") == 0) {
      cmpNaive();
    }else if (strcmp(argv[1], "naive") == 0) {
      naive(cin, cout);
    }else {
      cerr << "Unknown argument.\n";
      exit(1);
    }
  }else {
#endif
    body(cin, cout);
#if CMPNAIVE
  }
#endif
  return 0;
}

// ---- end cmpNaive.cc
// @@ !! LIM  -- end mark --

int naive(istream& cin, ostream& cout) {
  ll N, M; cin >> N >> M;

  ll cnt = 0;

  auto nxt = [&](const auto& rF, auto& vec, ll i) -> bool {
    if (i < 0) return false;
    vec.at(i)++;
    while (true) {
      while (true) {
	if (vec.at(i) == M) break;
	auto chk = [&]() -> bool {
	  for (ll j = 0; j < i; j++) {
	    if (vec.at(j) == vec.at(i)) return false;
	  }
	  return true;
	};
	if (chk()) return true;
	vec.at(i)++;
      }
      if (!rF(rF, vec, i - 1)) {
	vec.at(i) = i;
	return false;
      }
      vec.at(i) = 0;
    }
  };

  vector<ll> vecA(N);
  vector<ll> vecB(N);
  iota(vecA.begin(), vecA.end(), 0);
  iota(vecB.begin(), vecB.end(), 0);
  cnt = 0;
  auto chkAB = [&]() -> bool {
    for (ll i = 0; i < N; i++) {
      if (vecA.at(i) == vecB.at(i)) return false;
    }
    return true;
  };

  while (true) {
    while (true) {
      if (chkAB()) cnt++;
      if (!nxt(nxt, vecB, N-1)) break;
    }
    if (!nxt(nxt, vecA, N-1)) break;
  }
  cout << cnt << endl;
  return 0;
}



int body(istream& cin, ostream& cout) {
  ll N, M; cin >> N >> M;
  Comb cb(M);
  Fp varA = cb.fact(M) / cb.fact(M - N);
  DLOG("varA", varA);
  Fp varB = varA;
  bool neg = true;
  for (ll i = 1; i <= N; i++) {
    Fp x = cb.comb(N, i) * cb.fact(M - i) / cb.fact(M - N);
    if (neg) varB -= x;
    else     varB += x;
    neg = !neg;
    DLOG("i", i, "x", x);
  }
  cout << varA * varB << endl;


  return 0;
}



Measured memory_bytes: 11088