import java.util.*;

public class Yuki369{
 public static void main(String[] args){
  Scanner sc = new Scanner(System.in);
  long N=sc.nextInt();
  long M=0;
  for(int i=0;i<N;i++){
   long a= sc.nextInt();
   M =  M + a;
  }
  long yuki = sc.nextInt();
  System.out.println(M-yuki);
 }
}