import java.util.Scanner;

public class Main {
	public static void main(String[] a) {
		Scanner s = new Scanner(System.in);
		int[] p=new int[6];
		int i=0,b;for(;6>i;)p[i++]=s.nextInt();
		b=(p[4]-p[1]>0)?p[4]-p[1]:0;
		System.out.println(p[0]-b+((p[5]-p[2]-b>0)?p[2]+b:p[5]));
	}
}