use std::collections::HashMap;
use std::error::Error;
use std::fs::File;
use std::io::BufReader;
use std::io::prelude::*;

fn main() -> std::io::Result<()> {
    let mut f = File::open("input")?;
    let mut data = String::new();

    f.read_to_string(&mut data)?;

    for lineA in data.lines() {
        for lineB in data.lines() {
            let mut a = lineA.chars();
            let mut b = lineB.chars();
            let mut diffCount = 0;
            let mut pairs = a.zip(b);

            for (aChar, bChar) in pairs {
                if aChar != bChar {
                    diffCount += 1;
                }
            }

            if diffCount == 1 {
                println!("lineA: {} lineB: {}", lineA, lineB);
            }
        }
    }

    Ok(())
}