freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-271-modular-cubes-part-1.english.md

---
id: 5900f47b1000cf542c50ff8d
challengeType: 5
title: 'Problem 271: Modular Cubes, part 1'
---

## Description
<section id='description'>
For a positive number n, define S(n) as the sum of the integers x, for which 1<x<n andx3≡1 mod n.


When n=91, there are 8 possible values for x, namely : 9, 16, 22, 29, 53, 74, 79, 81.
Thus, S(91)=9+16+22+29+53+74+79+81=363.

Find S(13082761331670030).
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler271()</code> should return 4617456485273130000.
    testString: assert.strictEqual(euler271(), 4617456485273130000, '<code>euler271()</code> should return 4617456485273130000.');

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='js-seed'>

```js
function euler271() {
  // Good luck!
  return true;
}

euler271();
```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```
</section>