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

public class Solution {

    static long longestSequence(List<Long> a) {
        //  Return the length of the longest possible sequence of moves.
        long total = 0;
        
        for(int i=0; i<a.size(); i++){
            long sizeOfPiece = a.get(i);
            long pieceTotal = 0;

            //System.out.println("sizeOfPiece: " + sizeOfPiece);


            long mod = sizeOfPiece%2;
            //System.out.println("mod: " + mod);
            
            pieceTotal += sizeOfPiece;

            pieceTotal += sizeOfPiece/2;
            pieceTotal += 1;
            
            //System.out.println("pieceTotal: " + pieceTotal);
            
            total += pieceTotal;
        }
        
        return total;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        List<Long> a = new ArrayList<Long>();
        for(int a_i = 0; a_i < n; a_i++){
            a.add(in.nextLong());
        }
        long result = longestSequence(a);
        System.out.println(result);
        in.close();
    }
}