# 521. Longest Uncommon Subsequence I

## Problem

Given two strings a and b, return the length of the longest uncommon subsequence between a and b. If the longest uncommon subsequence does not exist, return -1.

An uncommon subsequence between two strings is a string that is a subsequence of one but not the other.

A subsequence of a string s is a string that can be obtained after deleting any number of characters from s.

- For example, “abc” is a subsequence of “aebdc” because you can delete the underlined characters in “aebdc” to get “abc”. Other subsequences of “aebdc” include “aebdc”, “aeb”, and “” (empty string).

Example 1:

```
Input: a = "aba", b = "cdc"
Output: 3
Explanation: One longest uncommon subsequence is "aba" because "aba" is a subsequence of "aba" but not "cdc".
Note that "cdc" is also a longest uncommon subsequence.
```

Example 2:

```
Input: a = "aaa", b = "bbb"
Output: 3
Explanation: The longest uncommon subsequences are "aaa" and "bbb".
```

Example 3:

```
Input: a = "aaa", b = "aaa"
Output: -1
Explanation: Every subsequence of string a is also a subsequence of string b. Similarly, every subsequence of string b is also a subsequence of string a.
```

Constraints:

- 1 <= a.length, b.length <= 100
- a and b consist of lower-case English letters.

## Code

```
class Solution {
public int findLUSlength(String a, String b) {
if (a.equals(b)){
return -1;
}
return Math.max(a.length(), b.length());
}
}
```

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522. Longest Uncommon Subsequence II