diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..600d2d3
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.vscode
\ No newline at end of file
diff --git a/#1/.gitignore b/course/1/.gitignore
similarity index 100%
rename from #1/.gitignore
rename to course/1/.gitignore
diff --git a/#2/CMakeLists.txt b/course/2/CMakeLists.txt
similarity index 100%
rename from #2/CMakeLists.txt
rename to course/2/CMakeLists.txt
diff --git a/#2/build/.gitignore b/course/2/build/.gitignore
similarity index 100%
rename from #2/build/.gitignore
rename to course/2/build/.gitignore
diff --git a/#2/main.cpp b/course/2/main.cpp
similarity index 100%
rename from #2/main.cpp
rename to course/2/main.cpp
diff --git a/course/3/CMakeLists.txt b/course/3/CMakeLists.txt
new file mode 100644
index 0000000..5df2b2b
--- /dev/null
+++ b/course/3/CMakeLists.txt
@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.12)
+
+project(HelloWorldProject VERSION 1.0.0)
+
+add_library(
+    HelloLibrary
+    hello-library.hpp
+    hello-library.cpp
+)
+
+add_executable(HelloApp main.cpp)
+
+target_link_libraries(HelloApp PRIVATE HelloLibrary)
\ No newline at end of file
diff --git a/course/3/build/.gitignore b/course/3/build/.gitignore
new file mode 100644
index 0000000..c96a04f
--- /dev/null
+++ b/course/3/build/.gitignore
@@ -0,0 +1,2 @@
+*
+!.gitignore
\ No newline at end of file
diff --git a/course/3/hello-library.cpp b/course/3/hello-library.cpp
new file mode 100644
index 0000000..c09f3b9
--- /dev/null
+++ b/course/3/hello-library.cpp
@@ -0,0 +1,7 @@
+#include "hello-library.hpp"
+#include <iostream>
+
+void HelloLibrary::showHello()
+{
+    std::cout<<"Hello world"<<std::endl;
+}
\ No newline at end of file
diff --git a/course/3/hello-library.hpp b/course/3/hello-library.hpp
new file mode 100644
index 0000000..67ba62e
--- /dev/null
+++ b/course/3/hello-library.hpp
@@ -0,0 +1,9 @@
+#ifndef HELLO_LIBRARY_HPP
+#define HELLO_LIBRARY_HPP 1
+
+namespace HelloLibrary
+{
+    void showHello();
+}
+
+#endif
\ No newline at end of file
diff --git a/course/3/main.cpp b/course/3/main.cpp
new file mode 100644
index 0000000..e3788ee
--- /dev/null
+++ b/course/3/main.cpp
@@ -0,0 +1,8 @@
+#include <iostream>
+#include "hello-library.hpp"
+
+int main()
+{
+    HelloLibrary::showHello();
+    return 0;
+}
\ No newline at end of file