Geometric progression

Geometric progression is defined as a sequence of , where each next element is obtained by multiplying the previous one with a number q.

For example 100, 200, 400, 800, 1600, ... is a geometric progression, where b1 = 100 and q = 2.

So, to obtain the n-th number in the sequence when having the first element and the number q, one can use the formula:

Given the first number in the sequence , the number q, and the number n, print the n-th element of the sequence .