Solution
T. R. Dawson The Chess Amateur, Feb. 1927
15+16. Black to play. Indicate a move Black must have played
Here, the parity argument tells us that Black played an even number of moves (with his Knights and Rooks).
White's King Rook has been captured in the South-East corner. We are told that Black has the move, thus the white Rook has been captured on g1 explaining how White has played an odd number of moves.
Solution: Black did play Nh3xRg1 (because the wN could not come from f3 without disturbing wKe1) and not the "obvious" Ng3xRh1 !!! (NB: Black also played Ng1-h3.)