Performing two or more tasks at the same time is known as 'Dovetailing.' This approach allows tasks to be completed efficiently by overlapping them. For example, Ria washes dishes while cooking, utilizing her time effectively.
On the day of her examination, Riya sharpened her pencil from both ends as shown below. 
The diameter of the cylindrical and conical part of the pencil is 4.2 mm. If the height of each conical part is 2.8 mm and the length of the entire pencil is 105.6 mm, find the total surface area of the pencil.