#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

long int longestSequence(int a_size, long int* a) {
    //  Return the length of the longest possible sequence of moves.
    int count=0;
    for(int i=0;i<a_size;i++)
    {
        if(a[i]==1)
        {
            count=1;
        }
        else
            if(a[i]%2==1)
            {
                count=count+a[i]+1;
            }
        else
            if(a[i]%2==0)
            {
                count=count+a[i]*2-2;
            }
        
    }
    return count;
}

int main() {
    int n; 
    scanf("%i", &n);
    long int *a = malloc(sizeof(long int) * n);
    for (int i = 0; i < n; i++) {
       scanf("%li",&a[i]);
    }
    long int result = longestSequence(n, a);
    printf("%ld\n", result);
    return 0;
}