import java.util.*;

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 ans = aw;
    ans -= Math.max(0, c - ab);
    ans += Math.min(bw, d);
    System.out.println(ans);
  }
}