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
a2a4
a2a3
b2b4
b2b3
c2c1
c2b3
c2b1
g2g4
g2g3
h2h4
h2h3
c3b1
c3b5
c3d1
c3d5
c3a4
c3e2
c3e4
c4b3
c4a6
c4b5
c4f1
c4e2
c4d3
c4g8
c4f7
c4e6
c4d5
b7a7
b7b3
b7b4
b7b5
b7b6
b7h7
b7g7
b7f7
b7e7
b7d7
b7c7
b7b8

## Board State Fen
4kb1r/pR5p/3r4/5p2/2B1p3/2N5/PPK3PP/8 w - - 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
a2a4
a2a3
b2b4
b2b3
c2c1
c2b3
c2b1
g2g4
g2g3
h2h4
h2h3
c3b1
c3b5
c3d1
c3d5
c3a4
c3e2
c3e4
c4b3
c4a6
c4b5
c4f1
c4e2
c4d3
c4g8
c4f7
c4e6
c4d5
b7a7
b7b3
b7b4
b7b5
b7b6
b7h7
b7g7
b7f7
b7e7
b7d7
b7c7
b7b8

## Board State Fen
4kb1r/pR5p/3r4/5p2/2B1p3/2N5/PPK3PP/8 w - - 0 21
assistant
b7a7