import java.util.Scanner;

public class Test {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		int aw, ab, bw, bb, x, y;
		aw = sc.nextInt();
		ab = sc.nextInt();
		bw = sc.nextInt();
		bb = sc.nextInt();
		x = sc.nextInt();
		y = sc.nextInt();
		bw += Math.max(0, x - ab);
		aw -= Math.max(0, x - ab);
		aw += Math.min(y, bw);
		System.out.println(aw);
	}
}