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++) {
			a[i] = sc.nextInt();
			sum += a[i] - 1;
		}
		System.out.println(sum);

	}

}
