import java.util.Scanner;

public class Study03 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a = sc.nextLine();
		int first = Integer.parseInt(a);

		String sss = sc.nextLine();
		String [] q = sss.split(" ");
		
		int num = 0;
		int[] sds = new int[q.length];
		for(int i=0;i<q.length;i++){
			sds[i] = Integer.parseInt(q[i]);
			num += sds[i];
			
		}

		int last = sc.nextInt();
		
		System.out.println(num-last);

	}

}