# UVa 913

From Algorithmist

## 913 - Joana and the Odd Numbers[edit]

## Summary[edit]

The only problem here is to calculate the last number of the n-th line. Bruteforce won't do it

## Explanation[edit]

First you can calculate the number of numbers per line. That is

Now you know how many numbers you have in one line. To get the last number of the n-th line, you need to know how many numbers there were before that line + the number of numbers in that line. So you can simply sum that up

The last number of the n-th is then:

Now you can simply calculte the sum:

## Gotcha's[edit]

- You need to use long long int to do the calculations