【模板】Lucas定理

C(n,m)%p=(C(n%p,m%p)%p * C(n/p,m/p)%p)%p

#include<iostream>
#include<cstdio>
#include<cstring>
#define Mo 10007
#define ll long long
using namespace std;
const int N=10010;
ll fac[N];
ll n,m;
void exgcd(ll a,ll b,ll &x,ll &y){
    if(!b){x=1;y=0;return;}
    else{exgcd(b,a%b,y,x);y-=(a/b)*x;}
}
ll inv(ll a){
    ll x,y;
    exgcd(a,10007,x,y);
    return (x%Mo+Mo)%Mo;
}
ll C(ll n,ll m){
    if(m==0) return 1;
    if(n<m) return 0;
    ll ret;
    ret=(ll)((ll)fac[n]*inv(fac[m]))%Mo;
    ret=(ll)((ll)ret*inv(fac[n-m]))%Mo;
    return ret;
}
ll Lucas(ll n,ll m){
    ll ans=1;
    while(n&&m){
        ll n1=n%Mo,m1=m%Mo;
        ans=(ll)((ll)ans*C(n1,m1))%Mo;
        n=(ll)(n/Mo);
        m=(ll)(m/Mo);
    }
    return ans;
}
int main(){
// freopen("in.txt","r",stdin);
// freopen("out.txt","w",stdout);
    scanf("%lld%lld",&n,&m);
    fac[0]=1;//Important
    fac[1]=1;
// for(int i=1;i<=5;i++) printf("%lld\n",inv(i));
    for(int i=2;i<=Mo;i++) fac[i]=(fac[i-1]*i)%Mo;
    printf("%lld\n",Lucas(n,m));
    return 0;
}