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
c1a1
c1b1
c1e1
c1d1
c1c7
c1c6
c1c5
c1c4
c1c3
c1c2
f1d1
f1e1
g1h1
a2a4
a2a3
b2a1
b2a3
b2c3
d2b4
d2c3
d2e1
d2c2
d2d1
d2d3
f2f4
f2f3
g2e4
g2f3
g2h1
g2h3
h2h4
h2h3
e3d1
e3f5
e3c2
e3c4
e3g4
g3g4
d4c2
d4c6
d4e6
d4b5
d4f3
d4f5

## Board State Fen
r2q1rk1/2pbppbp/3p1np1/1n1P4/1p1N4/1P2N1P1/PB1QPPBP/2R2RK1 w - - 6 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
c1a1
c1b1
c1e1
c1d1
c1c7
c1c6
c1c5
c1c4
c1c3
c1c2
f1d1
f1e1
g1h1
a2a4
a2a3
b2a1
b2a3
b2c3
d2b4
d2c3
d2e1
d2c2
d2d1
d2d3
f2f4
f2f3
g2e4
g2f3
g2h1
g2h3
h2h4
h2h3
e3d1
e3f5
e3c2
e3c4
e3g4
g3g4
d4c2
d4c6
d4e6
d4b5
d4f3
d4f5

## Board State Fen
r2q1rk1/2pbppbp/3p1np1/1n1P4/1p1N4/1P2N1P1/PB1QPPBP/2R2RK1 w - - 6 18
assistant
d4b5