
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
Sven wrote five different one-digit positive integers on a blackboard. He discovered that none of the sums of two different numbers on the board equaled 10. Which of the following numbers did Sven definitely write on the blackboard?
A 1
B 2
C 3
D 4
E 5

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