OnlineJudge 3 现已推出。点此体验新版：FormulaCheck | SDUT OnlineJudge

### FormulaCheck

Time Limit: 1000 ms
Memory Limit: 65536 KiB

#### Problem Description

The formula for computing the sum of the first n positive whole numbers is based on the idea of finding their average and then multiplying that by the number of numbers.

The average of the numbers between 1 and n is given by

**Hence the sum of the number must be**

Write a Java application program to check if this formula is correct.

#### Input

A positive number

#### Output

If this formula is correct,please give the output true.

#### Sample Input

3 9

#### Sample Output

true true

#### Hint

#### Source

maxj