import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try (Scanner scan = new Scanner(System.in)) {
            int n = Integer.parseInt(scan.next());
            int sum = 0;
            for(int i=0; i<n; i++) {
                sum += (Integer.parseInt(scan.next()));
            }
            int m = Integer.parseInt(scan.next());
            System.out.println(sum-m);
        }
    }
}