Program to find the root of the quadratic equation

C      Program to find the root of the quadratic equation
        write(*,*)'Enter the values of a,b,c'
        read(*,*)a,b,c
        d=b*b-(4.0*a*c)
        if (d.eq.0)then
        write(*,*)'The root is real and equal.'
        x1=-b/(2.0*a)
        write(*,*)'The equal root is :',x1
        else if (d.gt.0)then
        write(*,*)'The roots are real and distinct.'
        x1=(-b+sqrt(d))/(2.0*a)
        x2=(-b-sqrt(d))/(2.0*a)
        write(*,*)'The roots are :',x1,' and ',x2
        else
        write(*,*)'The roots are distinct but imaginary.'
        x1=(-b)/(2.0*a)
        x2=sqrt(-d)/(2.0*a)
        write(*,*)'The first root is :',x1,'+i',x2
        write(*,*)'The second root is :',x1,'-i',x2
        end if
        end