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.

The first line of the input file contains an integer number x (1 ≤ x ≤ 10⁹).

Output an integer number — the answer to the problem.

sample input

sample output

1

3

sample input

sample output

2

5

 #include<iostream>

 #include<string.h>

 #include<stdio.h>

 #include<ctype.h>

 #include<algorithm>

 #include<stack>

 #include<queue>

 #include<set>

 #include<math.h>

 #include<vector>

 #include<map>

 #include<deque>

 #include<list>

 using namespace std;

 int main()

 {

     int x;

     scanf("%d",&x);

     printf("%d\n",*x+);

     return ;

 }