#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
long int fib(long int n)
{
   if (n <= 1)
      return n;
   return fib(n-1) + fib(n-2);
}
 
// Returns number of ways to reach s'th stair
long int countWays(long int s)
{
    return fib(s + 1);
}
 
/*long int cal(long int data){
    int sum1=1;
    if(data%2 == 1)
        return 1;
    else if(data%2 ==0){
        while(data%2 ==0){
            int temp = data/2;
            sum +=temp;
            data = data/temp;
        }    
    }
    
    
}*/

long int longestSequence(int a_size, long int* a) {
    //  Return the length of the longest possible sequence of moves.
    long int sum=0;
    for(int i=0;i<a_size;i++)
        sum = sum + countWays(a[i]);
    
    return sum;
}

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