import java.util.*; 

public class test {
 public static void main(String[] args){
  Scanner sc = new Scanner(System.in);
		
  int a = sc.nextInt();
  int b[] = new int[a];
  int sum = 0;

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

  int c = sc.nextInt();

  System.out.println(sum - c);
 }
}