use std::io::{BufRead, BufReader};
use std::fs::File;

fn main (){
    // let filename = "./input_example.txt";
    let filename = "./input.txt";
    let file = BufReader::new(File::open(filename).expect("Unable to open file"));
    let mut accum: u32 = 0;

    for line in file.lines() { 
        let mut first_num: char = 'z';
        let mut last_num: char = 'z';
        // println!("{}", line.unwrap());
        for c in line.unwrap().to_string().chars() {
            if '0' <= c && c <= '9' {
                if first_num == 'z' {
                    first_num = c;
                }
                last_num = c;
            }
        }

        let mut line_num = String::from(first_num);
        line_num.push(last_num);
        // println!("first: {}, last: {}", first_num, last_num);
        // println!("line_num: {}", line_num);
        accum += line_num.parse::<u32>().unwrap();
    }

    println!("Total lines are: {}", accum);
}