# 1492. The kth Factor of n

<https://leetcode.com/problems/the-kth-factor-of-n>

## Description

Given two positive integers `n` and `k`.

A factor of an integer `n` is defined as an integer `i` where `n % i == 0`.

Consider a list of all factors of `n` sorted in **ascending order**, return *the* `kth` *factor* in this list or return **-1** if `n` has less than `k` factors.

**Example 1:**

```
**Input:** n = 12, k = 3
**Output:** 3
**Explanation:** Factors list is [1, 2, 3, 4, 6, 12], the 3rd factor is 3.
```

**Example 2:**

```
**Input:** n = 7, k = 2
**Output:** 7
**Explanation:** Factors list is [1, 7], the 2nd factor is 7.
```

**Example 3:**

```
**Input:** n = 4, k = 4
**Output:** -1
**Explanation:** Factors list is [1, 2, 4], there is only 3 factors. We should return -1.
```

**Example 4:**

```
**Input:** n = 1, k = 1
**Output:** 1
**Explanation:** Factors list is [1], the 1st factor is 1.
```

**Example 5:**

```
**Input:** n = 1000, k = 3
**Output:** 4
**Explanation:** Factors list is [1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, 125, 200, 250, 500, 1000].
```

**Constraints:**

* `1 <= k <= n <= 1000`

## ac

```java
```