import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    long answer =0;
    for(int i=0;i<n;i++){
      answer=answer+sc.nextLong();
    }
    answer=answer-n;
    System.out.println(answer);
  }
  

  
}
