ZOJ Problem Set - 2865
This task is very simple.
You are to calculate Σik (1 <= i <= n).
There are multiple cases in the input.
Each case begins with two integer n and k (0 <= n <= 1050, 1 <= k <= 100).
For each test, print the answer in a single line.
2 3 3 2
Author: SHANG, Zechao
Source: ZOJ Monthly, June 2007