import java.util.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    
    long sum = 0;

    for(int i = 0 ; i < n ; ++i){
      long a = sc.nextInt();
      sum += a;
    }

    System.out.println(sum - n);
    
  }
}