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
e4b1
e4c2
e4d3
e4c6
e4d5
e4f3
e4g6
e4f5
b6b5
e6e5
e7a3
e7b4
e7c5
e7d6
e7h4
e7g5
e7f6
f7f5
f7f6
g7g5
g7g6
h7h5
h7h6
a8a3
a8a4
a8a5
a8a6
a8a7
a8c8
a8b8
d8b8
d8c8
d8d1
d8d2
d8d3
d8d4
d8d5
d8d6
d8d7
d8e8
f8g8
f8e8

## Board State Fen
r2r1k2/1p2bppp/1p2p3/8/4b3/P1B1NP2/1P4PP/R2RK3 b - - 0 21
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
e4b1
e4c2
e4d3
e4c6
e4d5
e4f3
e4g6
e4f5
b6b5
e6e5
e7a3
e7b4
e7c5
e7d6
e7h4
e7g5
e7f6
f7f5
f7f6
g7g5
g7g6
h7h5
h7h6
a8a3
a8a4
a8a5
a8a6
a8a7
a8c8
a8b8
d8b8
d8c8
d8d1
d8d2
d8d3
d8d4
d8d5
d8d6
d8d7
d8e8
f8g8
f8e8

## Board State Fen
r2r1k2/1p2bppp/1p2p3/8/4b3/P1B1NP2/1P4PP/R2RK3 b - - 0 21
assistant
e4c6