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
b4b5
b4a4
a5a4
c5b3
c5b7
c5d3
c5d7
c5a4
c5a6
c5e4
c5e6
g7g5
g7g6
h7h5
h7h6
d8c6
d8e6
d8b7
d8f7

## Board State Fen
3n3N/6pp/8/p1nKPP2/1k6/8/PP4PP/8 b - - 0 31
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
b4b5
b4a4
a5a4
c5b3
c5b7
c5d3
c5d7
c5a4
c5a6
c5e4
c5e6
g7g5
g7g6
h7h5
h7h6
d8c6
d8e6
d8b7
d8f7

## Board State Fen
3n3N/6pp/8/p1nKPP2/1k6/8/PP4PP/8 b - - 0 31
assistant
b4b5