8/PPPPPP2/6r1/8/7P/r5pK/1p6/1R1N1nkn w - - 0 1
You have black bailing out into a materially lost position by playing this line: 1.a8(R) Rb3 2.b8(R) Rd3 3.d8(R) Rxd1. Black can keep forcing white to find more difficult lines by continuing across the 3rd rank. Black could have even played 2. ....Rc3 instead of jumping to the d-file. The main line is 1.a8(R) Rb3 2.b8(R) Rc3 3.c8(R)......etc. until the black rook reaches the f-file.
Yancey, I don't understand what move do you have in mind?
Alena, you have main idea, but not the main line. Black doesn't need to cooperate with 3. ....Rxd1. Black doesn't even need to skip the c3 square with the rook at move 2 either.
Sir , where do you find these amazing puzzles
hope I am right.
1.a8=Q to stop mate by g7