lucas模板

 ll PowMod(ll a,ll b,ll MOD){
     ll ret=;
     while(b){
         if(b&) ret=(ret*a)%MOD;
         a=(a*a)%MOD;
         b>>=;
     }
     return ret;
 }
 ll fac[];
 ll Get_Fact(ll p)
 {
     fac[]=;
     for(int i=;i<=p;i++)
         fac[i]=(fac[i-]*i)%p;
 }
 ll Lucas(ll n,ll m,ll p){
     ll ret=;
     while(n&&m){
         ll a=n%p,b=m%p;
         if(a<b) return ;
         ret=(ret*fac[a]*PowMod(fac[b]*fac[a-b]%p,p-,p))%p;
         n/=p;
         m/=p;
     }
     return ret;
 }