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As soon as you solve the chess puzzle, the snowdrift blocking your path to Santa's Workshop melts away. You can now see a path leading straight to the workshop's decorated entrance.

When you finally arrive at Santa's Workshop, you see that the entrance is guarded by a large mechanism resembling a chessboard. It seems like this device, complete with gears and clockwork components, requires a specific sequence to unlock. Positioned beneath the board are four chess pawns, indicating that they need to be placed on particular squares.

David Snowell inspects the mechanism with a discerning eye. "Classic Grinchuk," he comments. "He's locked the workshop because he knew we would need access to the chess gear inside to face him. He's always one step ahead!"

Wesley Snow picks up the four pawns, dusting off the snow, and hands them to you.

Magnus Carolsen leans in, his gaze fixed on the chessboard. "It’s not just where we place them," he observes, "but also the move we make after placing each pawn."

Wesley points to some small engravings next to the board. "Look here," he says. "These symbols seem to suggest that a mate-in-two needs to be found for each placement."

In summary, White will place a White pawn on any free square, so that White to play can force a mate in two (not a helpmate, but a regular checkmate). Give all 4 possible solutions. For each solution, you only need to write which square to place the pawn on, and White's first move in the sequence that leads to a mate in 2. Please give the answer as 4 different solutions separated by comma, where each solution is on the format "square to place the pawn on: move".

Example answer: "b2: b4, b2: Rh1, f2: g5, g7: g8=Q"

Here's the board editor, and here's Offerspill Discord server, if you're confused.