package no149;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int aw = sc.nextInt();
		int ab = sc.nextInt();
		int bw = sc.nextInt();
		int bb = sc.nextInt();
		int c = sc.nextInt();
		int d = sc.nextInt();

		int db = Math.min(ab, c);
		aw -= (c - db);
		bw += (c - db);
		ab -= db;
		bb += db;

		int dw = Math.min(bw, d);
		bw -= dw;
		aw += dw;
		System.out.println(aw);
	}

}