diff --git a/src/main/java/com/github/hcsp/pet1/Cat.java b/src/main/java/com/github/hcsp/pet1/Cat.java
new file mode 100644
index 0000000..782f19b
--- /dev/null
+++ b/src/main/java/com/github/hcsp/pet1/Cat.java
@@ -0,0 +1,4 @@
+package com.github.hcsp.pet1;
+
+public class Cat {
+}
diff --git a/src/main/java/com/github/hcsp/pet2/Dog.java b/src/main/java/com/github/hcsp/pet2/Dog.java
new file mode 100644
index 0000000..0567003
--- /dev/null
+++ b/src/main/java/com/github/hcsp/pet2/Dog.java
@@ -0,0 +1,4 @@
+package com.github.hcsp.pet2;
+
+public class Dog {
+}