When all prefabs are removed write +1 how?

Question

Arrays

prefab in the array, you need to make sure that when you click on it, it is deleted and writes +1 to the variable when all prefabs are deleted.
In principle, it is impossible to delete elements in an Array, how can this be written otherwise through a sheet?
public GameObject[] krugi=new GameObject[10];
private void OnMouseDown()
{
Destroy(krugi[???]); //How to make that when you click on the circle, this particular circle is deleted?
}

Answer 1

Use List<GameObject>. Then everything is simple:
private void OnMouseDown()
{
Mylist.Remove(gameObject);
Destroy(gameObject);
}