1st step

Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "variables"
+version = "0.1.0"

src/main.rs

@@ -1,3 +1,6 @@
 fn main() {
-    println!("Hello, world!");
+    let mut x = 5;
+    println!("The value of x is: {}", x);
+    x = 6;
+    println!("The value of x is: {}", x);
 }