<|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
 As shown in the figure, each small shape represents a number (the large box is only used to separate rows and columns), and the numbers on the right and below represent the sum of all numbers in that row or column (each row and column has 6 numbers). If $O$ represents 6, then $\Delta=$ $\qquad$ 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
4
As shown in the figure, each small shape represents a number (the large box is only used to separate rows and columns), and the numbers on the right and below represent the sum of all numbers in that row or column (each row and column has 6 numbers). If $O$ represents 6, then $\Delta=$ $\qquad$
test