<|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
 Some of the digits in the following correct addition have been replaced by the letters \( P, Q, R, \) and \( S \), as shown.
What is the value of \( P+Q+R+S \)?
\[
\begin{array}{r}
P 45 \\
+\quad Q R \quad S \\
\hline
654
\end{array}
\] 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
15
Some of the digits in the following correct addition have been replaced by the letters \( P, Q, R, \) and \( S \), as shown.
What is the value of \( P+Q+R+S \)?
\[
\begin{array}{r}
P 45 \\
+\quad Q R \quad S \\
\hline
654
\end{array}
\]
test