Sente's turn to play.This is a Yagura endgame position where Gote took the 13 pawn with Lx13 just after Sente had dropped a Pawn on 13 engaging in the edge attack(For Firefox users, please forward one move from the displayed position to have the problem. Sorry, this cannot be displayed on some smartphones). Please find a 9-move-mate-line from here. You have two silvers in hand and your attacking pieces on the board are the 41 Tokin, 68 Bishop, 25kNight, 19 Lance and some more Pawns which are sufficient enough to deliver a mate with the pieces in hand. This problem and the next ones will show you how effective the edge attack will be when Gote's Silver does not come to 24 and stays on 33 in Yagura games. I think you will find the importance of Gote's S-24 to protect the edge when Sente tries to attack the edge file with N-25 paradoxically through these problems. You can replay the answer line by clicking the arrow directing to the right under the diagram. Also, an exclamation mark sometimes appears there on a specific move during your replay, then click it and you can read my comments on that move.