/* convert factored number natural number:  a^exp * b^exp * ... z^exp -> N */
int ProdPrimestoNum(int *PF,int *EF)
{
 int H,J,K,Pow,Prod=1;

 while (*PF)
  {
   H=*PF; K=*EF; Pow=1;
   for (J=1; J<=K; J++) Pow*=H;
   Prod*=Pow;  PF++; EF++;
  }
 return Prod;
}