def workbook(n, k, arr):
    # Write your code here
    
    current_page_no = 0
    special_problem_count = 0
    for chapter in range(1, n+1):
        pages = math.ceil(arr[chapter-1] / k)
        current_problems = 0
        while pages > 0:
            current_page_no += 1
            problems_on_current_page = k if (arr[chapter-1] - current_problems) > k else arr[chapter-1] - current_problems
            if current_page_no > current_problems and current_page_no <= (current_problems+problems_on_current_page):
                special_problem_count += 1
            current_problems += problems_on_current_page
            pages -= 1            
    return special_problem_count