Problem : Write a Python program that asks user to input a positive integer n and prints out certain numbers.
a. Print the first n cubes.
For example, if n = 4, the output is:
1
8
27
64
b. Print perfect cubes < n.
For example, if n = 30, the output is:
1
8
27
c. Print the sum of i**3 for all 1 <= i <= n.
For example, if n = 5, the output is:
225
(Use while loops)