Consider the series

0, 0 + 1, 0 + 1 + 2, 0 + 1 + 2 + 3, 0 + 1 + 2 + 3 + 4, … = 0, 1, 3, 6, 10, … |

Write a program that, for every given natural number n, prints the first number of the series greater than or equal to n.

Input

Input consists of a sequence of natural numbers n.

Output

For every n, print the first number of the series 0, 1, 3, 6, … that is greater than or equal to n.

Public test cases

**Input**

6 7 1 2

**Output**

6 10 1 3

Information

- Author
- Salvador Roura
- Language
- English
- Translator
- Carlos Molina
- Original language
- Catalan
- Other languages
- Catalan
- Official solutions
- C++ Java Python
- User solutions
- C C++ Java Python