import java.util.Scanner;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;

class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int c = 0;
        for(int i=0; i<n; i++) {
            c += in.nextInt();
        }

        int v = in.nextInt();

        System.out.println(c-v);

        in.close();
    }
}