Exercise $3\mathrm{.}2$a $$ Pyramid Number Problem

A pyramidal number has the form $1^2+2^2+3^2+.......$

for example the forth pyramidal number is $30$ because:

$1^2+2^2+3^2^4^2=1+4+9+16=30$

It is also known as the cannonball stacking number becasue it represents how much spherical cannonballs

can be stacked in a pyramid shape with a given number of rows.

Your program should:

$1)$ Ask the user how many rows of cannonballs they want to stack

$2)$ Calculate the total number of cannonballs that will create the pyramid with the specified rows