回顾：创建一个书籍结构体

use std::io;

// TODO：在这里定义 Book 结构体，包含 title、author、year 和 pages 字段

fn main() {
    // 读取书名
    let mut title = String::new();
    io::stdin().read_line(&mut title).expect("Failed to read line");
    let title = title.trim().to_string();
    
    // 读取作者姓名
    let mut author = String::new();
    io::stdin().read_line(&mut author).expect("Failed to read line");
    let author = author.trim().to_string();
    
    // 读取出版年份
    let mut year_input = String::new();
    io::stdin().read_line(&mut year_input).expect("Failed to read line");
    let year: i32 = year_input.trim().parse().expect("Failed to parse year");
    
    // 读取页数
    let mut pages_input = String::new();
    io::stdin().read_line(&mut pages_input).expect("Failed to read line");
    let pages: i32 = pages_input.trim().parse().expect("Failed to parse pages");
    
    // TODO：使用输入值创建 Book 结构体的实例
    
    // TODO：按要求的格式输出图书信息
}