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
a5a4
b6b5
d6c6
d6d1
d6d2
d6d3
d6d4
d6d5
d6e6
f6f5
g6h7
g6h6
g6f7
d7a7
d7b7
d7c7
d7f7
d7e7
d7d8

## Board State Fen
1R6/3r2p1/1p1r1pk1/p7/1p4PP/1P2R3/1P3P2/5K2 b - - 0 42
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
a5a4
b6b5
d6c6
d6d1
d6d2
d6d3
d6d4
d6d5
d6e6
f6f5
g6h7
g6h6
g6f7
d7a7
d7b7
d7c7
d7f7
d7e7
d7d8

## Board State Fen
1R6/3r2p1/1p1r1pk1/p7/1p4PP/1P2R3/1P3P2/5K2 b - - 0 42
assistant
d6d4