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

//入力が必ず-mod<a<modの時.
template<const int mod>
struct modint{ //mod変更が不可能.
    public:
    long long v = 0;
    static void setmod(int m){} //飾り.
    static constexpr long long getmod(){return mod;}
    modint(){v = 0;} modint(int a){v = a<0?a+mod:a;} modint(long long a){v = a<0?a+mod:a;}
    modint(unsigned int a){v = a;} modint(unsigned long long a){v = a;}
    long long val()const{return v;}
 
    modint &operator=(const modint &b) = default;
    modint operator+()const{return (*this);}
    modint operator-()const{return modint(0)-(*this);}
    modint operator+(const modint b)const{return modint(v)+=b;}
    modint operator-(const modint b)const{return modint(v)-=b;}
    modint operator*(const modint b)const{return modint(v)*=b;}
    modint operator/(const modint b)const{return modint(v)/=b;}
    modint operator+=(const modint b){
        v += b.v; if(v >= mod) v -= mod;
        return *this;
    }
    modint operator-=(const modint b){
        v -= b.v; if(v < 0) v += mod; 
        return *this;
    }   
    modint operator*=(const modint b){v = v*b.v%mod; return *this;}
    modint operator/=(modint b){ //b!=0 mod素数が必須.
        if(b == 0) assert(false);
        int left = mod-2;
        while(left){if(left&1) *this *= b; b *= b; left >>= 1;}
        return *this;
    }
    modint operator++(){*this += 1; return *this;}
    modint operator--(){*this -= 1; return *this;}
    modint operator++(int){*this += 1; return *this;}
    modint operator--(int){*this -= 1; return *this;}
    bool operator==(const modint b)const{return v == b.v;}
    bool operator!=(const modint b)const{return v != b.v;}
    bool operator>(const modint b)const{return v > b.v;}
    bool operator>=(const modint b)const{return v >= b.v;}
    bool operator<(const modint b)const{return v < b.v;}
    bool operator<=(const modint b)const{return v <= b.v;}
    modint pow(long long n)const{
        modint ret = 1,p = v;
        if(n < 0) p = p.inv(),n = -n;
        while(n){
            if(n&1) ret *= p;
            p *= p; n >>= 1;
        }
        return ret;
    }
    modint inv()const{return modint(1)/v;} //素数mod必須.
};
using mint = modint<1000000000>;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    long long N,M; cin >> N >> M;
    N /= 1000; N %= M;
    
    vector<int> E(M+1);
    for(int i=2; i<=M; i++){
        int v = i;
        for(int k=2; k*k<=v; k++) while(v%k == 0) E.at(k)++,v /= k;
        if(v != 1) E.at(v)++;
    }
    for(int i=2; i<=N; i++){
        int v = i;
        for(int k=2; k*k<=v; k++) while(v%k == 0) E.at(k)--,v /= k;
        if(v != 1) E.at(v)--;
    }
    for(int i=2; i<=M-N; i++){
        int v = i;
        for(int k=2; k*k<=v; k++) while(v%k == 0) E.at(k)--,v /= k;
        if(v != 1) E.at(v)--;
    }

    mint answer = 1;
    for(int i=2; i<=M; i++) answer *= mint(i).pow(E.at(i));
    cout << answer.v << endl;
}