program test22
  real x1, x2
  integer i
  x1=0
  x2=0
  do i=1,30000
     x1 = x1+ 1.0/i
  end do
  do i=30000,1,-1
     x2 = x2+ 1.0/i
  end do
  write(*,*) "x1=",x1
  write(*,*) "x2=",x2
end program test22