#include <bits/stdc++.h>

    // #include <iostream> // cout, endl, cin
    // #include <string> // string, to_string, stoi
    // #include <vector> // vector
    // #include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
    // #include <utility> // pair, make_pair
    // #include <tuple> // tuple, make_tuple
    // #include <cstdint> // int64_t, int*_t
    // #include <cstdio> // printf
    // #include <map> // map
    // #include <queue> // queue, priority_queue
    // #include <set> // set
    // #include <stack> // stack
    // #include <deque> // deque
    // #include <unordered_map> // unordered_map
    // #include <unordered_set> // unordered_set
    // #include <bitset> // bitset
    // #include <climits>
    // #include <cmath>
    // #include <iomanip>
    // #include <functional>
    // #include <numeric>
    // #include <random>
    
    using namespace std;

    #define int long long
    #define pb push_back
    #define eb emplace_back
    // #define F first
    // #define S second
    #define FOR(i,a,b) for(int (i)=(a);(i)<(int)(b);(i)++)
    #define rep(i,n) FOR(i,0,n)
    #define RFOR(i,a,b) for(int (i)=(a);(i)>=(int)(b);(i)--)
    #define rrep(i,n) RFOR(i,n,0)
    #define all(a) (a).begin(),(a).end()
    #define rall(a) (a).rbegin(),(a).rend()
    #define ve vector
    #define vi vector<int>
    #define vp vector<pair<int,int>>
    #define vvi vector<vector<int>>
    #define UNIQUE(a) sort(all(a)), a.erase(unique(all(a)), a.end())
    #define Double double
    // #define endl '\n'
    
    template<typename T> using pq = priority_queue<T,vector<T>,greater<T>>; 
    using ll = long long;
    using ld = long double;
    using UnWeightedGraph = vector<vector<int>>;
    ll INF = LLONG_MAX / 4 - 100;
    int IINF = INT_MAX / 4;
    ll mod = 1e9 + 7;
    int dx[] = {1,0,-1,0}, dy[] = {0,1,0,-1};
    vector<ll> prime;
    
    long double pi = 3.141592653589793238;
        
    class fact {
    public:
        long long fmod = 1e9+7;
        vector<long long> fac, finv, inv;
        fact (int n, long long Mod = 1e9+7) {
            fmod = Mod;
            fac = vector<long long>(n + 1, 0);
            finv = vector<long long>(n + 1, 0);
            inv = vector<long long>(n + 1, 0);
            fac[0] = fac[1] = 1;
            finv[0] = finv[1] = 1;
            inv[1] = 1; 
            for (int i = 2; i < n + 1; i++) {
                fac[i] = fac[i-1] * i % fmod;
                inv[i] = mod - inv[mod%i] * (mod/i) % mod;
                finv[i] = finv[i-1] * inv[i] % mod;
            }
        }
        ll nCr(ll n, ll r) {if(n < r) return 0; return fac[n] * finv[r] % fmod * finv[n-r] % fmod;}
        ll POW(ll a, ll b) {ll c = 1; while (b > 0) {if (b & 1) {c = a * c%fmod;}a = a * a%fmod; b >>= 1;}return c;}
        inline int operator [] (int i) {return fac[i];}
        ll DeBuG(ll n, ll r);
    };
        
    void DEBUG(vector<int> a) {for(int i=0;i<a.size();i++)cout<<a[i]<<" ";cout<<endl;}
    void EMP(int x) {cout<<"!!!"<<x<<"!!!"<<endl;}
    ll GCD(ll a, ll b) {ll c; while (b != 0) {c = a % b; a = b; b = c;}return a;}
    ll LCM(ll a, ll b) {return (a / GCD(a, b)) * (b / GCD(a, b)) * GCD(a, b);}
    ll POW(ll a, ll b) {ll c = 1; while (b > 0) {if (b & 1) {c = a * c%mod;}a = a * a%mod; b >>= 1;}return c;}
    ld POW(ld a, ll b) {ld c = 1; while (b > 0) {if (b & 1) {c = a * c;}a = a * a; b >>= 1;}return c;}
    void PRI(ll n) {bool a[n + 1]; for (int i = 0; i < n + 1; i++) {a[i] = 1;}for (int i = 2; i < n + 1; i++) {if (a[i]) {prime.pb(i); ll b = i; while (b <= n) {a[b] = 0; b += i;}}}}
    template <typename T> T chmin(T& a, T b) {if(a>b)a=b;return a;}
    template <typename T> T chmax(T& a, T b) {if(a<b)a=b;return b;}
    bool isSqrt(ll a) {return pow(sqrt(a),2) == a ? 1 : 0;}
    void YesNo(bool a) {if (a) cout << "Yes"; else cout << "No"; cout << endl;}
    void yesno(bool a) {if (a) cout << "yes"; else cout << "no"; cout << endl;}
    void YESNO(bool a) {if (a) cout << "YES"; else cout << "NO"; cout << endl;}
    double dis(int x1, int x2, int y1, int y2) {
        return sqrt((double)abs(x1-x2)*(double)abs(x1-x2)+(double)abs(y1-y2)*(double)abs(y1-y2));
    }
    int ceili(int x, int y) {
        if (x % y == 0) return x / y;
        else return x / y + 1;
    }
    unsigned int randxor() {
        static unsigned int x=123456789,y=362436069,z=521288629,w=88675123;
        unsigned int t;
        t=(x^(x<<11));x=y;y=z;z=w; return( w=(w^(w>>19))^(t^(t>>8)) );
    }
    
    uint64_t xor64(void) {
        static uint64_t x = 88172645463325252ULL;
        x = x ^ (x << 7);
        return x = x ^ (x >> 9);
    }

    int frac[500005];

    void solve() {
        fact fac(500005);
        frac[0] = 1;
        FOR (i, 1, 500005) frac[i] = frac[i-1]*i%mod;
        int n, m; cin >> n >> m;
        int ans = frac[m] * POW(frac[m-n], mod-2) % mod;
        // cout << ans << endl;

        int mul = 0;
        rep (i, n+1) {
            int now = fac.nCr(n, i) * frac[m-i] % mod * POW(frac[m-n], mod-2) % mod;
            // cout << i << " " << now << endl;
            if (i%2) mul += mod-now;
            else mul += now;
            mul %= mod;
            // cout << mul << endl;
        }
        // cout << mul << endl;
        cout << ans * mul % mod << endl;
    }

    signed main() {
        cin.tie(0);
        ios::sync_with_stdio(false);
        solve();
    }


Measured memory_bytes: 18788