diff --git a/spreadsheet/src/domain/Cell.java b/spreadsheet/src/domain/Cell.java
new file mode 100644
index 0000000..fdae742
--- /dev/null
+++ b/spreadsheet/src/domain/Cell.java
@@ -0,0 +1,5 @@
+package domain;
+
+public class Cell {
+
+}
diff --git a/spreadsheet/src/fassade/Fassade.java b/spreadsheet/src/fassade/Fassade.java
new file mode 100644
index 0000000..87bb5c2
--- /dev/null
+++ b/spreadsheet/src/fassade/Fassade.java
@@ -0,0 +1,5 @@
+package fassade;
+
+public class Fassade {
+
+}
diff --git a/spreadsheet/src/spreadsheet/app/App.java b/spreadsheet/src/spreadsheet/app/Main.java
similarity index 84%
rename from spreadsheet/src/spreadsheet/app/App.java
rename to spreadsheet/src/spreadsheet/app/Main.java
index 183b6dd..5facb7c 100644
--- a/spreadsheet/src/spreadsheet/app/App.java
+++ b/spreadsheet/src/spreadsheet/app/Main.java
@@ -1,6 +1,6 @@
 package spreadsheet.app;
 
-public class App {
+public class Main {
 	public static void main(String... args) {
 		System.out.println("Hello World!");
 	}
diff --git a/spreadsheet/src/ui/App.java b/spreadsheet/src/ui/App.java
new file mode 100644
index 0000000..ec11bf2
--- /dev/null
+++ b/spreadsheet/src/ui/App.java
@@ -0,0 +1,5 @@
+package ui;
+
+public class App {
+
+}