import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solm {

    static long longestSequence(long[] a) {
        //  Return the length of the longest possible sequence of moves.
        long[] c = new long[a.length];
        long b = 0;
        long n =0;
        for(int i=0;i <a.length;i++){
           b = (a[i]*2)-2;
           c[i] = b;
        }
        for(int i=0;i<c.length;i++){
           n = n+c[i];
        }
        return n;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        long[] a = new long[n];
        for(int a_i = 0; a_i < n; a_i++){
            a[a_i] = in.nextLong();
        }
        long result = longestSequence(a);
        if(n==1){
          System.out.println(result); 
        }
        else{
          System.out.println(result-n);
        }
        
        in.close();
    }
}