def size_of_list(list):
    # return size of list
    return(len(list))
def add_elem_to_list(list, elem):
    # add elem to list and return the list
    list.append(elem)
    return(list)
def delete_elem_from_list(list, index = -1):
    # delete element from list, such that its index is index
    if len(list) <= index:
        return(list)
    else:
        return(list.pop(index))
def count_elements_in_list(list, x):
    # count elements in the list that are equal to x and return the count
    return(list.count(x))
def sort_list(list):
    # return sorted list
    return(list.sort())
def reverse(list):
    # return reversed list
	return(list.reverse())
#lst = [[1, -3, 0, 342], ["hello", "world", [213]],["dsd", "ass", [123]], [[5],[4],"d"]]
#a = 2
#print(delete_elem_from_list(lst,)sd)lplasdasasd
#list is not working lplplpasd
#asdasdjkjkjkjkas