implicit none
      real :: x,y,dy,x0,eps=0.00001
      integer :: kaisuu

      write(*,*) "ENTER TARGET NUMBER"
      read(*,*) x0

      x=10000.0
      do kaisuu=1,1000
       y=
       dy=
        if(abs(dy)<eps)then
          write(*,*) 'NG'
          stop
        endif
       x=x-y/dy
      write(*,'(1x,A,F18.6)') 'x=',x
       if(abs(y)<eps) exit
       if(abs(y/dy)<eps) exit
      enddo

      write(*,'(1x,A,F18.6)') 'x=',x
      write(*,'(1x,A,F18.6)') 'x2=',x*x
 
       end