2 10 50
  Ncall2 and  Itmx2 are the number of integrand
calls for one iteration and number of iteration
for the second (main) step of integration.  The
grid constructed on the first step is used but
the obtained integral estimation is thrown off.
  Because of the stratified sampling method is
used, it is desirable to increase Ncall2 taking
into account that the time of calculation is
proportional to Ncall2*Itmx2.
