import java.util.Scanner;

public class Main {

	public static void main (String[] args) {

		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int sum = 0;
		for (int i = 0; i < n; i++)
			sum += sc.nextInt();
		System.out.println(sum - sc.nextInt());
		sc.close();

	}

}