I need help with Python with best performance code

There is an array $A$ of $N$ integers sorted in non$-$decreasing order. In one move, you can either remove an integer from $A$ or insert an integer before or after any element of $A.$ The goal is to achieve an array in which all values $x$ that are present in the airaye acur exactly $x$ times.

For example, given $A=[1,1,3,4,4,4],$ value $1$ occurs twice, value $3$ occurs once and value $4$ occurs three times. You can remove one occurrence each of both $1$ and $3,$ and insert one occurrence $4,$ resulting in the array $1,4,4,4,4.$ In this array, every element $x$ occurs exactly $x$ times.

What is the minimum number of moves after which every value $x$ in the array occurs exactly $x$ times?

Write a function:

def solution $(A)$

that, given an array $A,$ returns the minimum number of moves after which every value $x$ in the array occurs exactly $x$ times. Note that it is permissible to remove some values entirely, if appropriate.

Examples:

Given $A=[1,1,3,4,4,4],$ your function should return $3,$ as described above.

Given $A=[1,2,2,2,5,5,5,8],$ your function should return $4.$ You can delete the $8$ and one occurrence of $2,$ and insert $5$ twice, resulting in $1,2,2,5,5,5,5,5$ after four moves. Notice that after the removals, there is no occurrence of $8$ in the array anymore.

Given $A=[1,1,1,1,3,3,4,4,4,4,4],$ your function should return $5.$

Given $A=[10,10,10],$ your function should return $3.$ You can remove all elements, resulting in an empty arrav.