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
e1b1
e1c1
e1d1
e1f1
e1e6
e1e5
e1e4
e1e3
e1e2
g1h2
g1h1
g1f1
a1d1
a1c1
a1b1
a1a2
f2f3
g2f1
g2d5
g2e4
g2f3
g2h1
g2h3
a3a4
c3b1
c3b5
c3d1
c3d5
c3a2
c3a4
c3e2
c3e4
d3b1
d3c2
d3a6
d3b5
d3c4
d3f1
d3e2
d3h7
d3g6
d3f5
d3e4
d3d1
d3d2
d3f3
d3e3
g3f1
g3f5
g3h1
g3h5
g3e2
g3e4
f4c1
f4d2
f4e3
f4d6
f4e5
h4h5
g5g6

## Board State Fen
3rr1k1/ppnq1ppp/2nbb3/3p2P1/3P1B1P/P1NQ2N1/1P3PB1/R3R1K1 w - - 15 19
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
e1b1
e1c1
e1d1
e1f1
e1e6
e1e5
e1e4
e1e3
e1e2
g1h2
g1h1
g1f1
a1d1
a1c1
a1b1
a1a2
f2f3
g2f1
g2d5
g2e4
g2f3
g2h1
g2h3
a3a4
c3b1
c3b5
c3d1
c3d5
c3a2
c3a4
c3e2
c3e4
d3b1
d3c2
d3a6
d3b5
d3c4
d3f1
d3e2
d3h7
d3g6
d3f5
d3e4
d3d1
d3d2
d3f3
d3e3
g3f1
g3f5
g3h1
g3h5
g3e2
g3e4
f4c1
f4d2
f4e3
f4d6
f4e5
h4h5
g5g6

## Board State Fen
3rr1k1/ppnq1ppp/2nbb3/3p2P1/3P1B1P/P1NQ2N1/1P3PB1/R3R1K1 w - - 15 19
assistant
f4d6