use std::error;
use std::fs::File;
use std::io::BufRead;
use std::io::BufReader;
use std::ops;

fn main() -> Result<(), Box<dyn error::Error>> {
	let f = File::open("input.txt")?;
	let reader = BufReader::new(f);

	let mut count: u32 = 0;
	for line in reader.lines() {
		let line = line?;
		let range_strs = line.split(",").collect::<Vec<&str>>();
		let range_a_u32 = range_strs[0].split("-").map(|x| x.parse::<u32>().unwrap()).collect::<Vec<u32>>();
		let range_a = ops::Range { start: range_a_u32[0], end: range_a_u32[1] + 1 };
		let range_b_u32 = range_strs[1].split("-").map(|x| x.parse::<u32>().unwrap()).collect::<Vec<u32>>();
		let range_b = ops::Range { start: range_b_u32[0], end: range_b_u32[1] + 1 };
		if range_a.contains(&range_b.start) || range_a.contains(&(range_b.end - 1)) || range_b.contains(&range_a.start) || range_b.contains(&(range_a.end - 1)) {
			count += 1;
		}
	}
	println!("Found {} overlapping ranges.", count);
    Ok(())
}