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];
		for(int i=0;i<n;i++){
			a[i]=sc.nextInt();
		}
		
		int sum=0;
		for(int i=0;i<n;i++){
			sum+=a[i]-1;
		}
		System.out.println(sum);
		
	}
}