Update 2024-01-25-lesson0.md

Author: stream-rahul

_posts/2024-01-25-lesson0.md

@@ -1,6 +1,6 @@
 ---
 layout: default
-title: "Lesson 0: Hello World in Rust"
+title: "Lesson 0: A copy program "
 date: 2024-01-25
 categories: rust
 permalink: /lesson0/
@@ -125,3 +125,8 @@ fn main() {          // (6) Program entry point. Compiler generates machine
 
 
 ```
+
+
+### Exercise 
+
+Let us do byte bby byte copy, exactly one byte. Read exactly one, write exactly one. No more and no less.