
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
Let  $p$  be a prime.  It is given that there exists a unique nonconstant function  $\chi:\{1,2,\ldots, p-1\}\to\{-1,1\}$  such that  $\chi(1) = 1$  and  $\chi(mn) = \chi(m)\chi(n)$  for all  $m, n \not\equiv 0 \pmod p$  (here the product  $mn$  is taken mod  $p$ ). For how many positive primes  $p$  less than  $100$  is it true that \[\sum_{a=1}^{p-1}a^{\chi(a)}\equiv 0\pmod p?\] Here as usual  $a^{-1}$  denotes multiplicative inverse.

*Proposed by David Altizio*

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