Chess puzzle (Checkmate)
Moves: 1. e4 Nc6 2. d4 e5 3. Nf3 exd4 4. Nxd4 Nxd4 5. Qxd4 Qf6 6. Be3 Qxd4 7. Bxd4 Ne7
8. Nc3 Nc6 9. Be3 Bb4 10. O-O-O Bxc3 11. bxc3 d6 12. Bb5 Bd7 13. c4 a6 14. Ba4
Ne5 15. Bb3 b6 16. f4 Ng4 17. Bd4 f6 18. h3 Nh6 19. g4 Bc6 20. Rhe1 O-O-O 21.
g5 Ng8 22. h4 h6 23. e5 hxg5 24. hxg5 dxe5 25. fxe5 Rh4 26. exf6 gxf6 27. gxf6
Bf3 28. f7 Bxd1 29. fxg8=Q Rxg8 30. Rxd1 Rgg4 31. Bf6 Rh2 32. c5 Rf4 33. Rd8+
Kb7 34. Bd5+ c6 35. Be5 Rf1+ 36. Kb2 Rxc2+ 37. Kxc2 cxd5 38. Rxd5 bxc5 39. Rxc5
Rf2+ 40. Kb3 Kb6 41. Rc4 Rf3+ 42. Kb4 Rh3 43. a4 *
Position (FEN): 8/8/pk6/4B3/PKR5/7r/8/8 b - - 0 43
Black to move.
Themes:  Endgame Mate in 1 
Puzzle rating: 904
Best move: a5#