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