<|im_start|>system
You are a helpful assistant. You first think about the reasoning process in the mind and then provide the user with the answer. You should try to truely solve the question by yourself without cheating.  <|im_end|>
<|im_start|>user
 There are N natural numbers. These natural numbers are consecutive from 1 to N, and the sum of even numbers in these numbers is 90 and the sum of odd numbers in these numbers is 100. What is the value of N? Show your work in <think> </think> tags. And return the final answer in <answer> </answer> tags.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user
19
There are N natural numbers. These natural numbers are consecutive from 1 to N, and the sum of even numbers in these numbers is 90 and the sum of odd numbers in these numbers is 100. What is the value of N?
test