<|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
 In certain cells of a rectangular board of size 101 by 99, there is a turtle in each cell. Every minute, each turtle simultaneously crawls to an adjacent cell of the board, sharing a side with the one they are currently in. Each subsequent move is made perpendicular to the previous one: if the previous move was horizontal - left or right, then the next one will be vertical - up or down, and vice versa. What is the maximum number of turtles that can move indefinitely on the board such that at each moment no cell contains more than one turtle? 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
9800
In certain cells of a rectangular board of size 101 by 99, there is a turtle in each cell. Every minute, each turtle simultaneously crawls to an adjacent cell of the board, sharing a side with the one they are currently in. Each subsequent move is made perpendicular to the previous one: if the previous move was horizontal - left or right, then the next one will be vertical - up or down, and vice versa. What is the maximum number of turtles that can move indefinitely on the board such that at each moment no cell contains more than one turtle?
test