The object of this puzzle is to construct a Minesweeper grid with a special property. The grid can be any shape, but it must have four labeled squares around the outer edge. Like this:

The four labeled squares must be labeled A, B, C, D, in that order going around the outer edge.

The objective is for a Minesweeper player to be able to conclude that A and C are the same, and B and D are the same, but not be able to conclude anything else. To be specific:

Place numbers in the grid to get a Minesweeper puzzle. This puzzle must have the following properties:

1. There are no safe clicks. That is, for any unnumbered square, there is a solution in which that square is a mine.
2. In any valid solution, A=C and B=D. (A=C means that A has a mine if and only if C does.)
3. For any mine-setting of A, B, C, and D that satisfies A=C and B=D, this setting extends to a solution of the whole grid.

Again, the grid can be any shape. The grid can even have holes in it, but understand that "outer edge" does not include the edge neighboring a hole. A, B, C, D can be placed anywhere along the outer edge, but must be in that order. Aim for the smallest grid!