[hdu-] Sum Problem

Problem Description

Hey, welcome to HDOJ(Hangzhou Dianzi University Online Judge).

In this problem, your task is to calculate SUM(n) = 1 + 2 + 3 + ... + n.

 

Input

The input will consist of a series of integers n, one integer per line.

 

Output

For each case, output SUM(n) in one line, followed by a blank line. You may assume the result will be in the range of 32-bit signed integer.

 

Sample Input

1100

 

Sample Output

15050

import java.util.Scanner;public class Main {public static void main(String[] args) {int n = 0;int sum = 0;Scanner scanner = new Scanner(System.in);while (scanner.hasNext()) {n = scanner.nextInt();for (int i = 1; i <= n; i++) {sum += i;}System.out.println(sum);System.out.println();sum = 0;}}}