<|im_start|>system
You are a helpful assistant. You first thinks about the reasoning process in the mind and then provides the user with the answer.<|im_end|>
<|im_start|>user
Using the numbers [50, 16, 12, 13], devise a mathematical expression that results in 30. You may utilize basic arithmetic operations (+, -, *, /) and each number can only be used once. Write your work in <think> </think> brackets and return your solution, showing all steps, in <answer> </answer> brackets, for example: <answer> (50 - 16) - (12 / 13) = 30 </answer>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>