7. For the following use a Karnaugh map to produce the minimal sum of products. For each shade each distinguished 1-cell. If more than one possible minimal answer is possible,

give the possible answers. \mathbf{H}(\mathbf{a}, \boldsymbol{b}, \mathbf{c}, \boldsymbol{d})=\sum(\mathbf{1}, \mathbf{9}, \mathbf{1 0}, \mathbf{1 1}, \mathbf{1 2})+u(5, \mathbf{6}, \mathbf{7}, \mathbf{1 3}, \mathbf{1 4}, \mathbf{1 5})