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);
	}
}