use std::thread;
use std::time::Duration;

fn main() {
    simulated_expensive_calculation(2);
}


fn simulated_expensive_calculation(intensity: i32) -> i32 {
    println!("Very expensive calculation...");
    thread::sleep(Duration::from_secs(2));
    intensity
}
fn main() {
    println!("Hello, world!");
}

--- 
+++ 
@@ -1,3 +1,13 @@
+use std::thread;
+use std::time::Duration;
+
 fn main() {
-    println!("Hello, world!");
+    simulated_expensive_calculation(2);
 }
+
+
+fn simulated_expensive_calculation(intensity: i32) -> i32 {
+    println!("Very expensive calculation...");
+    thread::sleep(Duration::from_secs(2));
+    intensity
+}
Implement function that will simulate expensive calculation
