diff --git a/Algorithms/0828. Unique Letter String/828. Unique Letter String.go b/Algorithms/0828. COPYRIGHT PROBLEM XXX/828. Unique Letter String.go
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rename to Algorithms/0828. COPYRIGHT PROBLEM XXX/828. Unique Letter String.go
diff --git a/Algorithms/0828. Unique Letter String/828. Unique Letter String_test.go b/Algorithms/0828. COPYRIGHT PROBLEM XXX/828. Unique Letter String_test.go
similarity index 100%
rename from Algorithms/0828. Unique Letter String/828. Unique Letter String_test.go
rename to Algorithms/0828. COPYRIGHT PROBLEM XXX/828. Unique Letter String_test.go
diff --git a/Algorithms/0828. Unique Letter String/README.md b/Algorithms/0828. COPYRIGHT PROBLEM XXX/README.md
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rename to Algorithms/0828. COPYRIGHT PROBLEM XXX/README.md
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@@ -2,33 +2,14 @@
 
 ## 题目
 
-A character is unique in string `S` if it occurs exactly once in it.
-
-For example, in string `S = "LETTER"`, the only unique characters are `"L"` and `"R"`.
-
-Let's define `UNIQ(S)` as the number of unique characters in string `S`.
-
-For example, `UNIQ("LETTER") = 2`.
-
-Given a string `S` with only uppercases, calculate the sum of `UNIQ(substring)` over all non-empty substrings of `S`.
-
-If there are two or more equal substrings at different positions in `S`, we consider them different.
-
-Since the answer can be very large, return the answer modulo `10 ^ 9 + 7`.
+THIS PROBLEM COPYRIGHT BELONGS TO CODILITY.COM
 
 **Example 1:**
 
-    Input: "ABC"
-    Output: 10
-    Explanation: All possible substrings are: "A","B","C","AB","BC" and "ABC".
-    Evey substring is composed with only unique letters.
-    Sum of lengths of all substring is 1 + 1 + 1 + 2 + 2 + 3 = 10
+
 
 **Example 2:**
 
-    Input: "ABA"
-    Output: 8
-    Explanation: The same as example 1, except uni("ABA") = 1.
 
 
 ## 题目大意
diff --git a/README.md b/README.md
index 90034f1f..258fef96 100644
--- a/README.md
+++ b/README.md
@@ -895,7 +895,7 @@
 | 0825 |  Friends Of Appropriate Ages                                 |                                                                                                                                               | 36.50%      |  Medium     |            |
 | 0826 |  Most Profit Assigning Work                                  | [Go](https://github.com/halfrost/LeetCode-Go/tree/master/Algorithms/0826.%20Most%20Profit%20Assigning%20Work)                                       | 35.90%      |  Medium     |            |
 | 0827 |  Making A Large Island                                       |                                                                                                                                               | 43.40%      |  Hard       |            |
-| 0828 |  Unique Letter String                                        |[Go](https://github.com/halfrost/LeetCode-Go/tree/master/Algorithms/0828.%20Unique%20Letter%20String)                                                                                                                                                | 39.80%      |  Hard       |            |
+| 0828 |  Unique Letter String                                        |[Go]()                                                                                                                                                | 39.80%      |  Hard       |            |
 | 0829 |  Consecutive Numbers Sum                                     |                                                                                                                                               | 33.50%      |  Hard       |            |
 | 0830 |  Positions of Large Groups                                   |                                                                                                                                               | 47.90%      |  Easy       |            |
 | 0831 |  Masking Personal Information                                |                                                                                                                                               | 42.20%      |  Medium     |            |
@@ -1454,7 +1454,7 @@
 |[713. Subarray Product Less Than K](https://leetcode.com/problems/subarray-product-less-than-k)| [Go](https://github.com/halfrost/LeetCode-Go/tree/master/Algorithms/0713.%20Subarray%20Product%20Less%20Than%20K)| Medium | O(n)| O(1)||
 |[763. Partition Labels](https://leetcode.com/problems/partition-labels)| [Go](https://github.com/halfrost/LeetCode-Go/tree/master/Algorithms/0763.%20Partition%20Labels)| Medium | O(n)| O(1)|❤️|
 |[826. Most Profit Assigning Work](https://leetcode.com/problems/most-profit-assigning-work)| [Go](https://github.com/halfrost/LeetCode-Go/tree/master/Algorithms/0826.%20Most%20Profit%20Assigning%20Work)| Medium | O(n log n)| O(n)||
-|[828. Unique Letter String](https://leetcode.com/problems/unique-letter-string)| [Go](https://github.com/halfrost/LeetCode-Go/tree/master/Algorithms/0828.%20Unique%20Letter%20String)| Hard | O(n)| O(1)|❤️|
+|[828. Unique Letter String](https://leetcode.com/problems/unique-letter-string)| [Go]()| Hard | O(n)| O(1)|❤️|
 |[838. Push Dominoes](https://leetcode.com/problems/push-dominoes)| [Go](https://github.com/halfrost/LeetCode-Go/tree/master/Algorithms/0838.%20Push%20Dominoes)| Medium | O(n)| O(n)||
 |[844. Backspace String Compare](https://leetcode.com/problems/backspace-string-compare)| [Go](https://github.com/halfrost/LeetCode-Go/tree/master/Algorithms/0844.%20Backspace%20String%20Compare)| Easy | O(n)| O(n) ||
 |[845. Longest Mountain in Array](https://leetcode.com/problems/longest-mountain-in-array)| [Go](https://github.com/halfrost/LeetCode-Go/tree/master/Algorithms/0845.%20Longest%20Mountain%20in%20Array)| Medium | O(n)| O(1) ||