<|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
Use the numbers [15, 15, 10, 5] to reach the target number 35. You can use basic arithmetic operations (+, -, *, /) and remember, each number can only be used once. Show your work in <think> </think> tags and return the final equation and answer: [Final equation and answer in <answer> ] format.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>