import java.util.Scanner;


public class Main_yukicoder149 {

    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 tmp = Math.max(0, c - ab);
        int ret = Math.min(bw + tmp, d) + aw - tmp;

        System.out.println(ret);
        
        sc.close();
    }
}