## Details

Let be `n`

an integer prime with `10`

e.g. `7`

.

`1/7 = 0.142857 142857 142857 ...`

.

We see that the decimal part has a cycle: `142857`

. The length of this cycle is `6`

. In the same way:

`1/11 = 0.09 09 09 ...`

. Cycle length is `2`

.

**Task**

Given an integer n (n > 1), the function cycle(n) returns the length of the cycle if n and 10 are coprimes, otherwise returns -1.

**Exemples:**

```
cycle(5) = -1
cycle(13) = 6 -> 0.076923 076923 0769
cycle(21) = 6 -> 0.047619 047619 0476
cycle(27) = 3 -> 0.037 037 037 037 0370
cycle(33) = 2 -> 0.03 03 03 03 03 03 03 03
cycle(37) = 3 -> 0.027 027 027 027 027 0
cycle(94) = -1
cycle(22) = -1 since 1/22 ~ 0.0 45 45 45 45 ...
```

Note

- Translators are welcome for all languages.