Scientific Problem

Scientific Problem

Time Limit:500MS Memory Limit:65536KB 64bit IO Format:%I64d & %I64u

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 ≤ 10⁹).

Output

Output an integer number — the answer to the problem.

Sample Input

sample input	sample output
1	3

sample input	sample output
2	5

题意：给出一个数n，找出一个数m，小于m的数中有n个比n大的数

#include<cstdio>
#include<string>
#include<iostream>
using namespace std;
string str[105];
int main()
{
    __int64 n;
    while(scanf("%I64d",&n)!=EOF)
     printf("%I64d\n",n*2+1);
    return 0;
}