Very Easy!!!
Easy
Execution time limit is 1 second
Runtime memory usage limit is 128 megabytes
You are given the value of n and a. Determine the answer for the following series:
Input
Two positive integers n and a.
Output
Print the value of sum. It is known that the result is no more than 10^18.
Examples
Input #1
Answer #1
Input #2
Answer #2
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Acceptance rate 20%