Update Readme.md

Author: wisdompeak

Readme.md

@@ -1191,6 +1191,7 @@
 [2642.Design-Graph-With-Shortest-Path-Calculator](https://github.com/wisdompeak/LeetCode/tree/master/Graph/2642.Design-Graph-With-Shortest-Path-Calculator) (M+)      
 [2959.Number-of-Possible-Sets-of-Closing-Branches](https://github.com/wisdompeak/LeetCode/tree/master/Graph/2959.Number-of-Possible-Sets-of-Closing-Branches) (M+)      
 [2976.Minimum-Cost-to-Convert-String-I](https://github.com/wisdompeak/LeetCode/tree/master/Graph/2976.Minimum-Cost-to-Convert-String-I) (M+)      
+[3387.Maximize-Amount-After-Two-Days-of-Conversions](https://github.com/wisdompeak/LeetCode/tree/master/Graph/3387.Maximize-Amount-After-Two-Days-of-Conversions) (H-)      
 * ``Hungarian Algorithm``    
 [1820.Maximum-Number-of-Accepted-Invitations](https://github.com/wisdompeak/LeetCode/tree/master/Graph/1820.Maximum-Number-of-Accepted-Invitations) (H)  
 [2123.Minimum-Operations-to-Remove-Adjacent-Ones-in-Matrix](https://github.com/wisdompeak/LeetCode/tree/master/Graph/2123.Minimum-Operations-to-Remove-Adjacent-Ones-in-Matrix) (H)