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();
			sum += a[i]-1;
		}
 
		System.out.println(sum);
	}
}