Rust Program to Subtract two Numbers from user input

Program

use std::io;
fn main() {
    println!("Subtraction of two numbers from user input:");
    println!("Enter the first integer number:");
    let mut first = String::new();
    io::stdin()
        .read_line(&mut first)
        .expect("Failed to read from stdin");
    let firsttrimmed = first.trim();
    let aint: i32 = firsttrimmed.trim().parse().ok().expect("Error! user entered value is not an integer");
    match firsttrimmed.parse::<u32>() {
        Ok(_i) => println!("Enter the second integer number:"),                
        Err(..) => println!("Error! user entered value is not an integer: {}", firsttrimmed),
    };  
    let mut second = String::new();
    io::stdin()
        .read_line(&mut second)
        .expect("Failed to read from stdin");
    let secondtrimmed = second.trim();
    let bint: i32 = secondtrimmed.trim().parse().ok().expect("Error! user entered value is not an integer");
    match secondtrimmed.parse::<u32>() {
    Ok(_i) => println!("Difference of numbers {0} and {1} is: {2}", aint, bint, aint - bint),
    Err(..) => println!("Error! user entered value is not an integer: {}", secondtrimmed),
    };  
}

Output

$ rustc SubtractTwoNumbersFromUserInput.rs
$ ./SubtractTwoNumbersFromUserInput 
Subtraction of two numbers from user input:
Enter the first integer number:
700
Enter the second integer number:
300
Difference of numbers 700 and 300 is: 400