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
a1c1
a1b1
d1a4
d1b3
d1c2
d1f3
d1e2
d1b1
d1c1
d1e1
d1d4
d1d3
d1d2
f1e1
g1h1
a2a4
a2a3
b2b3
f2f4
f2f3
g2g3
h2h4
h2h3
g4e2
g4f3
g4c8
g4d7
g4e6
g4f5
g4h3
g4h5
d5c3
d5c7
d5e3
d5e7
d5b6
d5f4
d5f6

## Board State Fen
1r1q1r1k/1b3p1p/p2p2p1/1p1Np1b1/1P2P1B1/8/PP3PPP/R2Q1RK1 w - - 0 18
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
a1c1
a1b1
d1a4
d1b3
d1c2
d1f3
d1e2
d1b1
d1c1
d1e1
d1d4
d1d3
d1d2
f1e1
g1h1
a2a4
a2a3
b2b3
f2f4
f2f3
g2g3
h2h4
h2h3
g4e2
g4f3
g4c8
g4d7
g4e6
g4f5
g4h3
g4h5
d5c3
d5c7
d5e3
d5e7
d5b6
d5f4
d5f6

## Board State Fen
1r1q1r1k/1b3p1p/p2p2p1/1p1Np1b1/1P2P1B1/8/PP3PPP/R2Q1RK1 w - - 0 18
assistant
a2a4