diff --git a/lesson_16/main.cpp b/lesson_16/main.cpp
new file mode 100644
index 0000000..40bc867
--- /dev/null
+++ b/lesson_16/main.cpp
@@ -0,0 +1,13 @@
+#include <iostream>
+
+int doubleNumber(int a)
+{
+	return a * 2;
+}
+
+int main()
+{
+	int a;
+	std::cin >> a;
+	std::cout << doubleNumber(a) << std::endl;
+}