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

#define ALL(obj) (obj).begin(),(obj).end()
#define SPEED cin.tie(0);ios::sync_with_stdio(false);

template<class T> using PQ = priority_queue<T>;
template<class T> using PQR = priority_queue<T,vector<T>,greater<T>>;

constexpr long long MOD = (long long)1e9 + 7;
constexpr long long MOD2 = 998244353;
constexpr long long HIGHINF = (long long)1e18;
constexpr long long LOWINF = (long long)1e15;
constexpr long double PI = 3.1415926535897932384626433L;

template <class T> vector<T> multivector(size_t N,T init){return vector<T>(N,init);}
template <class... T> auto multivector(size_t N,T... t){return vector<decltype(multivector(t...))>(N,multivector(t...));}
template <class T> void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; exit(0);}}
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) {o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o;}
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const multiset<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;}
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) {o << "{" << obj.first << ", " << obj.second << "}"; return o;}
template <template <class tmp>  class T, class U> ostream &operator<<(ostream &o, const T<U> &obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr)o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
void print(void) {cout << endl;}
template <class Head> void print(Head&& head) {cout << head;print();}
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) {cout << head << " ";print(forward<Tail>(tail)...);}
template <class T> void chmax(T& a, const T b){a=max(a,b);}
template <class T> void chmin(T& a, const T b){a=min(a,b);}
void YN(bool flg) {cout << (flg ? "YES" : "NO") << endl;}
void Yn(bool flg) {cout << (flg ? "Yes" : "No") << endl;}
void yn(bool flg) {cout << (flg ? "yes" : "no") << endl;}

/*
 * @title ModInt
 */
template<long long mod> class ModInt {
public:
	long long x;
	constexpr ModInt():x(0) {
		// do nothing
	}
	constexpr ModInt(long long y) : x(y>=0?(y%mod): (mod - (-y)%mod)%mod) {
		// do nothing
	}
	ModInt &operator+=(const ModInt &p) {
		if((x += p.x) >= mod) x -= mod;
		return *this;
	}
	ModInt &operator+=(const long long y) {
		ModInt p(y);
		if((x += p.x) >= mod) x -= mod;
		return *this;
	}
	ModInt &operator+=(const int y) {
		ModInt p(y);
		if((x += p.x) >= mod) x -= mod;
		return *this;
	}
	ModInt &operator-=(const ModInt &p) {
		if((x += mod - p.x) >= mod) x -= mod;
		return *this;
	}
	ModInt &operator-=(const long long y) {
		ModInt p(y);
		if((x += mod - p.x) >= mod) x -= mod;
		return *this;
	}
	ModInt &operator-=(const int y) {
		ModInt p(y);
		if((x += mod - p.x) >= mod) x -= mod;
		return *this;
	}
	ModInt &operator*=(const ModInt &p) {
		x = (x * p.x % mod);
		return *this;
	}
	ModInt &operator*=(const long long y) {
		ModInt p(y);
		x = (x * p.x % mod);
		return *this;
	}
	ModInt &operator*=(const int y) {
		ModInt p(y);
		x = (x * p.x % mod);
		return *this;
	}
	ModInt &operator^=(const ModInt &p) {
		x = (x ^ p.x) % mod;
		return *this;
	}
	ModInt &operator^=(const long long y) {
		ModInt p(y);
		x = (x ^ p.x) % mod;
		return *this;
	}
	ModInt &operator^=(const int y) {
		ModInt p(y);
		x = (x ^ p.x) % mod;
		return *this;
	}
	ModInt &operator/=(const ModInt &p) {
		*this *= p.inv();
		return *this;
	}
	ModInt &operator/=(const long long y) {
		ModInt p(y);
		*this *= p.inv();
		return *this;
	}
	ModInt &operator/=(const int y) {
		ModInt p(y);
		*this *= p.inv();
		return *this;
	}
	ModInt operator=(const int y) {
		ModInt p(y);
		*this = p;
		return *this;
	}
	ModInt operator=(const long long y) {
		ModInt p(y);
		*this = p;
		return *this;
	}
	ModInt operator-() const { return ModInt(-x); }
	ModInt operator++() { 
		x++;
		if(x>=mod) x-=mod;
		return *this; 
	}
	ModInt operator--() { 
		x--;
		if(x<0) x+=mod;
		return *this; 
	}
	ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
	ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
	ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
	ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
	ModInt operator^(const ModInt &p) const { return ModInt(*this) ^= p; }
	bool operator==(const ModInt &p) const { return x == p.x; }
	bool operator!=(const ModInt &p) const { return x != p.x; }
	ModInt inv() const {
		int a = x, b = mod, u = 1, v = 0, t;
		while(b > 0) {
			t = a / b;
			swap(a -= t * b, b);
			swap(u -= t * v, v);
		}
		return ModInt(u);
	}
	ModInt pow(long long n) const {
		ModInt ret(1), mul(x);
		while(n > 0) {
			if(n & 1) ret *= mul;
			mul *= mul;
			n >>= 1;
		}
		return ret;
	}
	friend ostream &operator<<(ostream &os, const ModInt &p) {
		return os << p.x;
	}
	friend istream &operator>>(istream &is, ModInt &a) {
		long long t;
		is >> t;
		a = ModInt<mod>(t);
		return (is);
	}
};
using modint = ModInt<MOD>;

/*
 * @title CombinationMod
 */
template<long long mod> class CombinationMod {
	vector<long long> fac,finv,inv;
public:
	CombinationMod(int N) : fac(N + 1), finv(N + 1), inv(N + 1) {
		fac[0] = fac[1] = finv[0] = finv[1] = inv[1] = 1;
		for (int i = 2; i <= N; ++i) {
			fac[i] = fac[i - 1] * i % mod;
			inv[i] = mod - inv[mod%i] * (mod / i) % mod;
			finv[i] = finv[i - 1] * inv[i] % mod;
		}
	}
	inline long long binom(int n, int k) {
		return ((n < 0 || k < 0 || n < k) ? 0 : fac[n] * (finv[k] * finv[n - k] % mod) % mod);
	}
	inline long long factorial(int n) {
		return fac[n];
	}
};

//verify https://atcoder.jp/contests/abc021/tasks/abc021_d

/*
 * @title SegmentTree
 */
template<class Operator> class SegmentTree {
	using TypeNode = typename Operator::TypeNode; 
	size_t length;
	size_t num;
	vector<TypeNode> node;
	vector<pair<size_t,size_t>> range;
public:

	//unitで初期化
	SegmentTree(const size_t num): num(num) {
		for (length = 1; length < num; length *= 2);
		node.resize(2 * length, Operator::unit_node);
		range.resize(2 * length);
		for (int i = 0; i < length; ++i) range[i+length] = make_pair(i,i+1);
		for (int i = length - 1; i >= 0; --i) range[i] = make_pair(range[(i<<1)+0].first,range[(i<<1)+1].second);
	}

	//vectorで初期化
	SegmentTree(const vector<TypeNode> & vec) : num(vec.size()) {
		for (length = 1; length < vec.size(); length *= 2);
		node.resize(2 * length, Operator::unit_node);
		for (int i = 0; i < vec.size(); ++i) node[i + length] = vec[i];
		for (int i = length - 1; i >= 0; --i) node[i] = Operator::func_node(node[(i<<1)+0],node[(i<<1)+1]);
		range.resize(2 * length);
		for (int i = 0; i < length; ++i) range[i+length] = make_pair(i,i+1);
		for (int i = length - 1; i >= 0; --i) range[i] = make_pair(range[(i<<1)+0].first,range[(i<<1)+1].second);
	}
 
	//同じinitで初期化
	SegmentTree(const size_t num, const TypeNode init) : num(num) {
		for (length = 1; length < num; length *= 2);
		node.resize(2 * length, Operator::unit_node);
		range.resize(2 * length);
		for (int i = 0; i < length; ++i) node[i+length] = init;
		for (int i = 0; i < length; ++i) range[i+length] = make_pair(i,i+1);
		for (int i = length - 1; i >= 0; --i) range[i] = make_pair(range[(i<<1)+0].first,range[(i<<1)+1].second);
	}
	
	//[idx,idx+1)
	void update(size_t idx, const TypeNode var) {
		if(idx < 0 || length <= idx) return;
		idx += length;
		node[idx] = Operator::func_merge(node[idx],var);
		while(idx >>= 1) node[idx] = Operator::func_node(node[(idx<<1)+0],node[(idx<<1)+1]);
	}

	//[l,r)
	TypeNode get(int l, int r) {
		if (l < 0 || length <= l || r < 0 || length < r) return Operator::unit_node;
		TypeNode vl = Operator::unit_node, vr = Operator::unit_node;
		for(l += length, r += length; l < r; l >>=1, r >>=1) {
			if(l&1) vl = Operator::func_node(vl,node[l++]);
			if(r&1) vr = Operator::func_node(node[--r],vr);
		}
		return Operator::func_node(vl,vr);
	}

	//return [0,length]
	int prefix_binary_search(TypeNode var) {
		if(!Operator::func_check(node[1],var)) return num;
		TypeNode ret = Operator::unit_node;
		size_t idx = 2;
		for(; idx < 2*length; idx<<=1){
			if(!Operator::func_check(Operator::func_node(ret,node[idx]),var)) {
				ret = Operator::func_node(ret,node[idx]);
				idx++;
			}
		}
		return min((idx>>1) - length,num);
	}

	//range[l,r) return [l,r]
	int binary_search(size_t l, size_t r, TypeNode var) {
		if (l < 0 || length <= l || r < 0 || length < r) return -1;
		TypeNode ret = Operator::unit_node;
		size_t off = l;
		for(size_t idx = l+length; idx < 2*length && off < r; ){
			if(range[idx].second<=r && !Operator::func_check(Operator::func_node(ret,node[idx]),var)) {
				ret = Operator::func_node(ret,node[idx]);
				off = range[idx++].second;
				if(!(idx&1)) idx >>= 1;			
			}
			else{
				idx <<=1;
			}
		}
		return off;
	}
};

//一点加算 区間最大
template<class T> struct NodeSumPointAdd {
	using TypeNode = T;
	inline static constexpr TypeNode unit_node = 0;
	inline static constexpr TypeNode func_node(TypeNode l,TypeNode r){return l+r;}
	inline static constexpr TypeNode func_merge(TypeNode l,TypeNode r){return l+r;}
	inline static constexpr bool func_check(TypeNode nodeVal,TypeNode var){return var == nodeVal;}
};

//Pow_Mod O(log(n))
long long PowMod(long long x, long long n, long long mod) {
    long long res = 1;
    for (; n > 0; n >>= 1, (x *= x) %= mod) if (n & 1) (res *= x) %= mod;
    return res;
}

//Inv_Mod O(log(mod))
long long InvMod(long long x, long long mod){
	return PowMod(x,mod-2,mod); 
}


int main() {
	ll N,M; cin >> N >> M;
	CombinationMod<MOD> CM(M);
	vector<modint> A(N+1,0);
	modint ans = 0;
	for(ll i = 0; i <= N; ++i) {
		modint cnt = 1;
		cnt *= CM.binom(M,i);
		cnt *= CM.factorial(i);
		cnt *= CM.binom(N,i);
		cnt *= CM.binom(M-i,N-i);
		cnt *= CM.factorial(N-i);
		cnt *= CM.binom(M-i,N-i);
		cnt *= CM.factorial(N-i);
		A[i]=cnt;
		ans += cnt*(1-2*(i%2));
	}
	cout << ans << endl;

    return 0;
}


Measured memory_bytes: 18596