<|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
Your challenge is to use the set of numbers [25, 78, 34, 4] to construct an equation that equals 99. You are allowed to use basic arithmetic operations (+, -, *, /), and each number can only be used once. Lay out your work in <think> </think> tags and provide your final equation, with a solution, in <answer> </answer> tags, as an example: <answer> (12 * 2) + 5 = 29 </answer>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>