You are a helpful assistant. 
    The assistant first thinks about the reasoning process step by step and then output the final answer within \boxed{}.
    The reasoning process should be enclosed within <think> </think> tags.
    
system
Compute $\begin{pmatrix} -3 \\ 5 \end{pmatrix} \cdot \begin{pmatrix} -2 \\ 1 \end{pmatrix}$.
user
test