Challenge: Black Rook Escapes from the Siege: A Brutal Imbalanced Endgame - Can you solve it?

The Black Rook on file 4, rank 7 is besieged, and the Black General on file 4, rank 8 is helpless. The Red Pawns on file 6, rank 9 and file 5, rank 9 form a 'Double Empty Pawn' formation threatening to capture the Black General. The Black Rook must find a way to escape or the Red Cannon on file 5, rank 1 will deliver the final blow.