import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int []A = new int[N];
		for(int i = 0; i < N; i++) {
			A[i] = scan.nextInt();
		}
		int v = scan.nextInt();
		scan.close();
		int sum = 0;
		for(int i = 0; i < N; i++) {
			sum += A[i];
		}
		System.out.println(sum - v);
	}
}