import java.util.*;

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