Given a 2-by-2 or 3-by-3 matrix H, CLAQR1 sets v to a
      scalar multiple of the first column of the product

      (*)  K = (H - s1*I)*(H - s2*I)

      scaling to avoid overflows and most underflows.

      This is useful for starting double implicit shift bulges
      in the QR algorithm.

          N is integer
              Order of the matrix H. N must be either 2 or 3.

          H is COMPLEX array of dimension (LDH,N)
              The 2-by-2 or 3-by-3 matrix H in (*).

          LDH is integer
              The leading dimension of H as declared in
              the calling procedure.  LDH.GE.N

          S1 is COMPLEX

          S2 is COMPLEX

          S1 and S2 are the shifts defining K in (*) above.

          V is COMPLEX array of dimension N
              A scalar multiple of the first column of the
              matrix K in (*).