import java.util.*;

public class Main {
    public static void main(String args[]) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        long sum = 0;
        for(int i = 0; i < n; i++)
        	sum += sc.nextLong();

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