> For the complete documentation index, see [llms.txt](https://jaywin.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jaywin.gitbook.io/leetcode/solutions/1015-smallest-integer-divisible-by-k.md).

# 1015. Smallest Integer Divisible by K

<https://leetcode.com/problems/smallest-integer-divisible-by-k>

## Description

Given a positive integer `k`, you need to find the **length** of the **smallest** positive integer `n` such that `n` is divisible by `k`, and `n` only contains the digit `1`.

Return *the **length** of* `n`. If there is no such `n`, return -1.

**Note:** `n` may not fit in a 64-bit signed integer.

**Example 1:**

```
**Input:** k = 1
**Output:** 1
**Explanation:** The smallest answer is n = 1, which has length 1.
```

**Example 2:**

```
**Input:** k = 2
**Output:** -1
**Explanation:** There is no such positive integer n divisible by 2.
```

**Example 3:**

```
**Input:** k = 3
**Output:** 3
**Explanation:** The smallest answer is n = 111, which has length 3.
```

**Constraints:**

* `1 <= k <= 105`

## ac

```java
```