<|im_start|>system
Please reason step by step, and put your final answer within \boxed{}.<|im_end|>
<|im_start|>user
Given the following crystal representation:
3.1 3.1 9.9
90 90 109
Al
0.00 0.00 0.71
Ag
0.81 0.00 0.68
Sn
0.81 0.00 0.30
Sn
0.00 0.00 0.19
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
3.1 3.1 9.9
90 90 109
Al
0.00 0.00 0.71
Ag
0.81 0.00 0.68
Sn
0.81 0.00 0.30
Sn
0.00 0.00 0.19
Identify the crystal system.