Given an array of size $n$.
$CGE$ denotes the value of $\text{current greatest element}$.

You can perform these action several times (probably zero):
$1.$ Choose any $\text{two equal elements}$, lets say their value is $val$
$2.$ Replace them by another integer $\text{new_val}$  s.t,  $\text{new_val}<=max(CGE,val+1)$

Note that if size of array is $S$ in step $1$ then it will be $S-1$ after the operation performed in step $2$.
And you can add new element after step $2$ anywhere in the array, this means order of elements in the array doesn't matter.

After performing the above action as many times as you want, you will have a resultant array $RES$.

Your task is to maximize $CGE$ of $RES$.

Input Format -

The first line contains a single integer $n$ which denotes the size of input array.

The second line of input contains n integers which denotes elements of input array.

Output Format -

Print a single integer CGE of RES.

Constraints -

$1 < n <= 10^5$

$-10^9 <= a_i <=10^9$