To check the speed of JCN Corporation new supercomputer it was decided to figure out the sum of first N (N < 10600) 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.
One line containing the result of calculations on the supercomputer.
Выведите N, the number entered by Chief Programmer.
Problem Author: Eugene Bryzgalov
Problem Source: Ural Collegiate Programming Contest, April 2001, Perm, English Round