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Rev

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Find the discrete logarithm

Task

Write a program/function that when given 3 positive integers \$a, b\$ and \$m\$ as input outputs a positive integer \$x\$ such that \$a^x\equiv b\ (\text{mod}\ m)\$ or that no such \$x\$ exists.

A reference implementation can be found here.

Constraints

You can expect \$a\$ and \$b\$ to be less than \$m\$.

Scoring

This is code-golf so shortest bytes wins.

Sample Testcases

# a, b, m -> x
10, 10, 50 -> 1
10, 100, 200 -> 2
10, 1, 127 -> 42
35, 541, 1438 -> 83
35, 541, 1438 -> 1519
1816, 2629, 3077 -> 223
3306, 4124, 5359 -> 1923
346, 406, 430 -> None
749430, 2427332, 2500918 -> 8025683
3442727916, 3990620294, 6638635157 -> 5731137125

Note: in the third testcase the solution cannot be 0 since the solution has to be a positive number

Answer*

If this is an answer to a challenge…

…Be sure to follow the challenge specification. However, please refrain from exploiting obvious loopholes. Answers abusing any of the standard loopholes are considered invalid. If you think a specification is unclear or underspecified, comment on the question instead.
…Try to optimize your score. For instance, answers to code-golf challenges should attempt to be as short as possible. You can always include a readable version of the code in addition to the competitive one. Explanations of your answer make it more interesting to read and are very much encouraged.
…Include a short header which indicates the language(s) of your code and its score, as defined by the challenge.

More generally…

…Please make sure to answer the question and provide sufficient detail.
…Avoid asking for help, clarification or responding to other answers (use comments instead).

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