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
代码语言：javascript复制#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;
}
