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

public class Solution {

    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();
        }
        int sum=0;
        for(int j=0;j<n;j++){
            if(a[j]%2!=0){
                sum+=1;
                sum+=a[j]+1;
               a[j]=a[j]-1;
                sum+=a[j]/2;
            }
            else{
              sum+=a[j]+1; 
                sum+=a[j]/2;
            }
            }
        System.out.println(sum);
        }
        
    }