import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int n = sc.nextInt();
		//		int[] a = new int[n];

		int sum = 0;
		for (int i = 0; i < n; i++) {
			sum += sc.nextInt() - 1;
		}

		System.out.println(sum);

		sc.close();
	}
}