implicit real*8 (a-h,o-z)
        do i=-500,300
        do j=-500,300
           x=i*.01
           y=j*.01
!          f=x**4+4.1*x**3+x**2-5.2*x+20.0+abs(y)**(1.0/6.0)
           f=x**4+4.1*x**3+x**2-5.2*x+20.0+y**4+4.1*y**3+y**2-5.2*y+20.0
           write(10,*) x,y,f
        enddo
        write(10,*)
        enddo
        end