import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.stream.Stream;

import static java.lang.System.in;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        int N = Integer.parseInt(reader.readLine());
        String[] inputs = reader.readLine().split(" ");
        long sum = 0;
        for (int i = 0; i < N; i++) {
            sum += Long.parseLong(inputs[i]);
        }
        long v = Long.parseLong(reader.readLine());
        System.out.println(sum-v);
    }
}