update Makefile
diff --git a/Makefile b/Makefile
index 21a5827..731c2ed 100644
--- a/Makefile
+++ b/Makefile
@@ -13,4 +13,4 @@
 	$(CC) $(DEBUG) -o $(TARGET) $(TARGET).cpp
 
 clean: 
-	$(RM) $(TARGET)
+	rm -f $(TARGET)