
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
The addition below is incorrect, and we need to determine the smallest digit that can be changed to make the addition correct for addition $\begin{tabular}{rr} & \texttt{7 5 3}\\ & \texttt{9 4 6}\\ & +\texttt{8 2 1}\\ \hline & \texttt{2 4 2 0} \end{tabular}$.

Present the answer in LaTex format: \boxed{Your answer}
user