import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

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

		System.out.println(sum - n);
		sc.close();
	}

}
