import java.util.Scanner;

public class yukicoder_149 {
	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);
		
		int aw = stdIn.nextInt();
		int ab = stdIn.nextInt();
		int bw = stdIn.nextInt();
		int bb = stdIn.nextInt();
		int c = stdIn.nextInt();
		int d = stdIn.nextInt();
		
		if (c <= ab) {
			bb += c;
			ab -= c;
		} else {
			bb += ab;
			bw += c - ab;
			aw -= c - ab;
			ab = 0;
		}
		
		if (d <= bw) {
			aw += d;
			bw -= d;
		} else {
			aw += bw;
			ab += d - bw;
			bb -= d - bw;
			bw = 0;
		}
		
		System.out.println(aw);
	}
}