[Sandbox](https://codegolf.meta.stackexchange.com/a/18348/82007)

There are special sets *S* of primes such that \$\sum\limits_{p\in S}\frac1{p-1}=1\$. In this challenge, your goal is to find the largest possible set of primes that satisfies this condition.

**Input**: None

**Output**: A set of primes which satisfies the conditions above.

This challenge is a [tag:code-challenge], where your score is the size of the set you output.

Examples of Valid Outputs and their scores
=

    {2} - 1
    {3,5,7,13} - 4
    {3,5,7,19,37} - 5
    {3,5,7,29,31,71} - 6

**Important**: This challenge doesn't require any code, simply the set. However, it would be helpful to see how you generated your set, which probably involves some coding.