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


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

	let mut sums: Vec<u32> = Vec::new();
	let mut current_sum: u32 = 0;
	for value in reader.lines() {
		let value = value.unwrap();
		if value == "" {
			sums.push(current_sum);
			current_sum = 0;
		} else {
			current_sum += value.parse::<u32>()?;
		}
	}
	sums.push(current_sum);
	sums.sort();
	sums.reverse();
	
	println!("{:?}", sums[..3].iter().sum::<u32>());
    Ok(())
}