#407. When the sum goes over S
You get S. Find the smallest n with 1 + 2 + ... + n > S.
### Input
One integer S (0 ≤ S ≤ 10⁹).
### Output
n.
Examples
Input
368688333
Output
27155
Input
127788481
Output
15987
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.