Singular Values & the SVD · Challenge problem

Let $A = \begin{pmatrix}1 & 1\\1 & 1\\1 & 1\end{pmatrix}$ and $b = \begin{pmatrix}1\\2\\6\end{pmatrix}$. The system $Ax = b$ has no solution and infinitely many least-squares solutions. Find $\|x^{+}\|^2$ for the minimum-norm least-squares solution $x^{+} = A^{+}b$.