Update README.md

Author: kamyu104

README.md

@@ -1098,7 +1098,7 @@
 1980 | [Find Unique Binary String](https://leetcode.com/problems/find-unique-binary-string/) | [C++](./C++/find-unique-binary-string.cpp) [Python](./Python/find-unique-binary-string.py) | _O(n)_ | _O(1)_ |  Medium |  | `Cantor Diagonalization` |
 1982 | [Find Array Given Subset Sums](https://leetcode.com/problems/find-array-given-subset-sums/)|[C++](./C++/find-array-given-subset-sums.cpp) [Python](./Python/find-array-given-subset-sums.py)| _O(n * 2^n)_     | _O(1)_         | Hard         | | Math, DP, OrderedDict |
 2001 | [Number of Pairs of Interchangeable Rectangles](https://leetcode.com/problems/number-of-pairs-of-interchangeable-rectangles/)|[C++](./C++/number-of-pairs-of-interchangeable-rectangles.cpp) [Python](./Python/number-of-pairs-of-interchangeable-rectangles.py)| _O(n)_     | _O(n)_         | Medium         | | Math |
-2005 | [Subtree Removal Game with Fibonacci Tree](https://leetcode.com/problems/subtree-removal-game-with-fibonacci-tree/)|[C++](./C++/subtree-removal-game-with-fibonacci-tree.cpp) [Python](./Python/subtree-removal-game-with-fibonacci-tree.py)| _O(1)_     | _O(1)_         | Hard         | | Math, `Sprague-Grundy Theorem`, `Colon Principle` |
+2005 | [Subtree Removal Game with Fibonacci Tree](https://leetcode.com/problems/subtree-removal-game-with-fibonacci-tree/)|[C++](./C++/subtree-removal-game-with-fibonacci-tree.cpp) [Python](./Python/subtree-removal-game-with-fibonacci-tree.py)| _O(1)_     | _O(1)_         | Hard         |🔒| Math, `Sprague-Grundy Theorem`, `Colon Principle` |
 
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