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
b2b4
b2b3
f2f4
f2f3
g3h3
g3h2
g3g2
g3f3
h4h5
a5a1
a5a2
a5a3
a5a4
a5f5
a5e5
a5d5
a5c5
a5b5
a5a6
g5h6
f6e4
f6e8
f6g4
f6g8
f6d5
f6d7
f6h5
f6h7

## Board State Fen
8/5pk1/p3nNpp/R5P1/3r3P/6K1/1P3P2/8 w - - 4 40
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
b2b4
b2b3
f2f4
f2f3
g3h3
g3h2
g3g2
g3f3
h4h5
a5a1
a5a2
a5a3
a5a4
a5f5
a5e5
a5d5
a5c5
a5b5
a5a6
g5h6
f6e4
f6e8
f6g4
f6g8
f6d5
f6d7
f6h5
f6h7

## Board State Fen
8/5pk1/p3nNpp/R5P1/3r3P/6K1/1P3P2/8 w - - 4 40
assistant
f6e8