Scientific Problem

Problem Description

Once upon a time Professor Idioticideasinventor was travelling by train. Watching cheerless landscape outside the window, he decided to invent the theme of his new scientific work. All of a sudden a brilliant idea struck him: to develop an effective algorithm finding an integer number, which is x times less than the sum of all its integer positive predecessors, where number x is given. As far as he has no computer in the train, you have to solve this difficult problem.

Input

The first line of the input file contains an integer number x (1 <= x <= 10^9).

Output

Output an integer number - the answer to the problem.

Example(s)

sample input sample output
1 3
2 5

Solution

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#include <bits/stdc++.h>

int main() {
std::ios::sync_with_stdio(false);

int x{};
std::cin >> x;

std::cout << (x << 1 | 1) << std::endl;
return 0;
}