diff --git a/README.md b/README.md
index e9d92a8604563df77f60ad591f5e85c46ff383bb..fa15452bf67072272bb110af06991cad960e3ae4 100644
--- a/README.md
+++ b/README.md
@@ -132,4 +132,11 @@ The signs used in the level will become the sign used in the game, so try to put
 12.<img src = "README_IMAGE/12.PNG" width = "30">
 13.<img src = "README_IMAGE/13.PNG" width = "30">
 14.<img src = "README_IMAGE/14.PNG" width = "30">
-15.<img src = "README_IMAGE/15.PNG" width = "30">
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+15.<img src = "README_IMAGE/15.PNG" width = "30">
+
+## Exisiting Bug
+
+1. A lag happened when frequently clicked the **restart button** and **start button**.
+2. When the game runs for a long time, it may causes **memory leak**
+
+Fortunately, bugs on the above are located.
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