import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] a = new int[n];
		long ans = 0;
		for(int i = 0; i < n; i++) {
			 ans += sc.nextInt()-1;
		}
		
		System.out.println(ans);
	}
}