To check the speed of JCN Corporation new supercomputer it was decided to figure out the sum of first *N* (*N* < 10^{600}) positive integers. Unfortunately, by the time the calculation was finished the Chief Programmer forgot the value of *N* he entered. Your task is to write the program (for personal computer), which would determine the value of *N* by the result calculated on supercomputer.

**Note:** JCN Corporation manufactures only reliable computers, and its programmers write only correctly working programs.

### Input

One line containing the result of calculations on the supercomputer.

### Output

Выведите *N*, the number entered by Chief Programmer.

### Sample

**Problem Author: **Eugene Bryzgalov

**Problem Source: **Ural Collegiate Programming Contest, April 2001, Perm, English Round