Given the available moves based on the current board state in FEN notation, think carefully about which move would be best, then make that move. Be sure to note your color indicated in the FEN notation before deciding.
## Available Moves
b4a4
b4b1
b4b2
b4b3
b4d4
b4c4
b4b8
b4b7
b4b6
b4b5
g6h7
g6h6
g6g7
g6f7
g6f6

## Board State Fen
8/8/6k1/3R2p1/1r2p1P1/4P3/5P2/5K2 b - - 22 68
system
You are a chess playing AI.
user
Given the available moves based on the current board state in FEN notation, think carefully about which move would be best, then make that move. Be sure to note your color indicated in the FEN notation before deciding.
## Available Moves
b4a4
b4b1
b4b2
b4b3
b4d4
b4c4
b4b8
b4b7
b4b6
b4b5
g6h7
g6h6
g6g7
g6f7
g6f6

## Board State Fen
8/8/6k1/3R2p1/1r2p1P1/4P3/5P2/5K2 b - - 22 68
assistant
b4b6