Chess puzzle (Checkmate)
Moves: 1. e4 c5 2. Nf3 d6 3. Nc3 Nf6 4. e5 dxe5 5. Nxe5 Nbd7 6. Bb5 a6 7. Nxd7 Bxd7 8.
Bxd7+ Qxd7 9. O-O e6 10. d3 Bd6 11. Bg5 Be7 12. Qf3 O-O 13. Rfe1 b5 14. Qh3 h6
15. Bh4 Rad8 16. Rad1 b4 17. Ne4 Nxe4 18. Bxe7 Qxe7 19. dxe4 Qf6 20. Qe3 Qxb2
21. Qxc5 Qxa2 22. Ra1 Qb2 23. Reb1 Qc3 24. Qxc3 bxc3 25. Rb3 Rd4 26. Rxc3 Rxe4
27. Rxa6 *
Position (FEN): 5rk1/5pp1/R3p2p/8/4r3/2R5/2P2PPP/6K1 b - - 0 27
Black to move.
Themes:  Endgame, Rook Endgame Back Rank Mate, Mate in 1 
Puzzle rating: 600
Best move: Re1#