use std::io::*;

fn main() {
    print!("How many numbers to read? ");
    stdout().flush().expect("the count of #chars flushed (which we then ignore).");
    // Because `print!` doesn't print a \n, and the OS may buffer
    // stdout waiting for a \n before it bothers printing.
    // We solve that by calling `flush()`.
    // (Then, we call `unwrap` to handle any Result::Err,
    // to keep the compiler from warning us of unhandled Err.)

    // Read first number
    let num_inputs = read_int_v2();
    // Loop to read remaining numbers
    for i in 0..num_inputs {
        print!("Lemme see number #{}: ", i + 1);
        stdout().flush().unwrap();
        let n = read_int_v2();
        println!("You gave me {}.", n);
    }
}

/* fn read_int_v1() -> u32 {
    let lines = std::io::stdin().lines(); // an iterator
    let line = lines.next(); // an Option<Result<String,...>>

    let attempted_num = match line {
        Ok(str) => str.trim().parse::<u32>(),
        Err(msg) => panic!("Failed to read line"),
    };

    // attempted_num is the result of `parse`: a Result<u32,..>
    // we COULD do another match (and panic); there is also a handy
    // Result method `unwrap_or`:
    return attempted_num.unwrap_or(0);

    //let input: u32 = input.trim().parse().expect("Line didn't contain an unsigned integer");
    //input
}
 */

fn read_int_v2() -> u32 {
    let mut input: String = String::new(); // Create empty string (growable)

    stdin().read_line(&mut input).expect("a line of input on stdin"); // Store next line of input in String

    let the_num_read: u32 = input
        .trim()
        .parse()
        .expect("a numeric string");  // also consider: .unwrap_or
    return the_num_read;
}