D. Saleem The Driver
time limit per test
1.5 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

Malabeh loves putting numbers into boxes. He puts $$$1$$$ in the first box, $$$2$$$ in the second, and so on, until the $$$n$$$-th box contains the number $$$n$$$.

One day, he asked his friend, the professional driver Saleem, to deliver all the boxes to the land of Samar.

But Ayham the trickster stole one box on the way.

Saleem only knows the sum of the numbers after the theft. Note that you don't know $$$n$$$.

Help Saleem to find the number on the stolen box.

Input

The only line of each test case contains a single integer $$$s$$$ ($$$1 \le s \le 10^{12}$$$) — the sum of the numbers on the remaining boxes after the theft.

Output

print a single integer — the number on the stolen box.

It is guaranteed that for each test case, there is exactly one unique answer.

Examples
Input
4
Output
2
Input
24
Output
4
Input
17
Output
4
Note

In the first testcase, the initial boxes were $$$1, 2$$$, and $$$3$$$. Ayham stole the box with the number $$$2$$$, so the remaining boxes are $$$1$$$ and $$$3$$$, which sum to $$$4$$$.

In the second testcase, the initial boxes were $$$1, 2, 3, 4, 5, 6$$$, and $$$7$$$. Ayham stole the box with the number $$$4$$$, so the remaining boxes are $$$1, 2, 3, 5, 6,$$$ and $$$7$$$, which sum to $$$24$$$.