use std::io::Read;

fn main() {
	let mut s = String::new();
	std::io::stdin().read_to_string(&mut s).ok();
	let mut n: Vec<i64> = s.split_whitespace().flat_map(str::parse).collect();
	let w = 0.max(n[4] - n[1]);
	n[0] -= w;
	n[2] += w;
	let w = n[2].min(n[5]);
	n[0] += w;
	println!("{}", n[0]);
}