import java.util.*;

class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int[] a = new int[N];
        int ans = 0;

        for(int i=0; i<N; i++){
            a[i] = sc.nextInt();
            ans += a[i] -1;
        }
        System.out.println(ans);
    }
}