import java.util.*;

public class Main {
    public static void main(String args[]) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int sum = 0;
        for (int i = 0; i < n; i++) {
            sum += scanner.nextInt() -1;
        }
        System.out.println(sum);
    }
}