---
id: 5900f3a51000cf542c50feb8
challengeType: 5
title: 'Problem 57: Square root convergents'
---
## Description
It is possible to show that the square root of two can be expressed as an infinite continued fraction.
√ 2 = 1 + 1/(2 + 1/(2 + 1/(2 + ... ))) = 1.414213...
By expanding this for the first four iterations, we get:
1 + 1/2 = 3/2 = 1.5
1 + 1/(2 + 1/2) = 7/5 = 1.4
1 + 1/(2 + 1/(2 + 1/2)) = 17/12 = 1.41666...
1 + 1/(2 + 1/(2 + 1/(2 + 1/2))) = 41/29 = 1.41379...
The next three expansions are 99/70, 239/169, and 577/408, but the eighth expansion, 1393/985, is the first example where the number of digits in the numerator exceeds the number of digits in the denominator.
In the first one-thousand expansions, how many fractions contain a numerator with more digits than denominator?
## Instructions
## Tests
```yml
tests:
- text: euler57() should return 153.
testString: assert.strictEqual(euler57(), 153, 'euler57() should return 153.');
```
## Challenge Seed
```js
function euler57() {
// Good luck!
return true;
}
euler57();
```