import java.util.*;
import java.math.*;
import java.io.*;
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();
		if(ab >= c) {
			bb += c;
			ab -= c;
		}
		else {
			bb += ab;
			bw += (c - ab);
			aw -= (c - ab);
			ab = 0;
			
		}
		if(bw >= d) {
			aw += d;
			bw -= d;
		}
		else {
			aw += bw;
		}
		System.out.println(aw);
	}
 }