import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No00000369_Main {
	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	public static void main(String[] args) throws IOException {
		int n = Integer.parseInt(br.readLine());
		String[] strArr = br.readLine().split(" ");
		int sum = 0;
		for(int i = 0; i < n; i++) {
			sum += Integer.parseInt(strArr[i]);
		}
		System.out.println(	sum - Integer.parseInt(br.readLine()));
	}
}