inverse_mod_process_02

// second types of template


ll nCr(ll n, ll r)
{


   ll p = 1, k = 1;


   if (n - r < r)
       r = n - r;


   if (r != 0)
   {
       while (r)
       {
           p *= n;
           k *= r;


           ll m = __gcd(p, k);


           p /= m;
           k /= m;


           n--;
           r--;
       }
   }


   else
       p = 1;
   return p;
}