typedef double HepDouble;
typedef int HepInt;

class HepJamesRandom {
public:
  HepDouble flat();

private:
  HepDouble u[97];
  HepDouble c, cd, cm;
  HepInt i97, j97;
};

HepDouble HepJamesRandom::flat()
{
   HepDouble uni;

   do {
      uni = u[i97] - u[j97];
      if ( uni < 0.0 ) uni++;
      u[i97] = uni;

      if (i97 == 0) i97 = 96;
      else i97--;

      if (j97 == 0) j97 = 96;
      else j97--;

      c -= cd;
      if (c < 0.0) c += cm;

      uni -= c;
      if (uni < 0.0) uni += 1.0;
   } while ( uni <= 0.0 || uni >= 1.0 );

   return uni;
}