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