import java.util.*;
import java.math.*;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		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);
	}

}
