Problem:
Score : 100 points

Problem Statement

A biscuit making machine produces B biscuits at the following moments: A seconds, 2A seconds, 3A seconds and each subsequent multiple of A seconds after activation.

Find the total number of biscuits produced within T + 0.5 seconds after activation.

Constraints

All values in input are integers.

1 \leq A, B, T \leq 20

Input

Input is given from Standard Input in the following format:

A B T

Output

Print the total number of biscuits produced within T + 0.5 seconds after activation.

Sample Input 1

3 5 7

Sample Output 1

10

Five biscuits will be produced three seconds after activation.

Another five biscuits will be produced six seconds after activation.

Thus, a total of ten biscuits will be produced within 7.5 seconds after activation.

Sample Input 2

3 2 9

Sample Output 2

6

Sample Input 3

20 20 19

Sample Output 3

0

Solution in Ruby (2.3.3) (judge verdict: Wrong Answer)

a,b,t = STDIN.read.chomp.split(" ")

tot_time = t.to_f + 0.5
time_span = a.to_f
buisquets_per_span = b.to_i

counter = 1
tot_buisquets = 0
time_passed = 0
while time_span < tot_time
  tot_buisquets += buisquets_per_span
  time_passed += time_span
  time_span = time_span * counter
  counter += 1
end
puts tot_buisquets