Find the minimum number of straight lines required to make the given figure.

Counting from the figure: horizontal lines are the top edge, rectangle top, inner box bottom and rectangle bottom (4). Vertical lines are the rectangle's two sides and the inner box's left, middle and right lines (5). Slanting lines are top-left to inner left corner, top-right to inner right corner, apex to both inner corners, both inner top corners to the bottom corners, and both inner bottom corners to the bottom corners (8). 4 + 5 + 8 = 17.