import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
        int n=sc.nextInt();
        int ans=0;
        int a=0;

        for(int i=0; i<n; i++){
            a=sc.nextInt();
            ans+=a;
        }
        int v =sc.nextInt();

        System.out.println(ans-v);

        sc.close();
	}
}