<|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
Find a unique and effective way to calculate the number 100 using the numbers 19, 13, 8, and 5 with basic arithmetic operations. Show all your working within the <think> block. Then, follow the guidelines to provide a fully-fledged answer underneath the prompt. Example format: <answer> 19 - 13 + 8 + 5 = 19 </answer>. <|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>