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();
            a[i]--;
            if(i != 0){
                a[0] += a[i];
            }
        }
        System.out.println(a[0]);
    }
}