---
id: 5900f40a1000cf542c50ff1d
challengeType: 5
title: 'Problem 158: Exploring strings for which only one character comes lexicographically after its neighbour to the left'
videoUrl: ''
localeTitle: ''
---

## Description
undefined

## Instructions
undefined

## Tests
<section id='tests'>

```yml
tests:
  - text: ''
    testString: 'assert.strictEqual(euler158(), 409511334375, "<code>euler158()</code> should return 409511334375.");'

```

</section>

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

<div id='js-seed'>

```js
function euler158() {
  // Good luck!
  return true;
}

euler158();

```

</div>



</section>

## Solution
<section id='solution'>

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