Problem:
Score : 100 points

Problem Statement

There are N children in AtCoder Kindergarten. Mr. Evi will arrange the children in a line, then give 1 candy to the first child in the line, 2 candies to the second child, ..., N candies to the N-th child. How many candies will be necessary in total?

Constraints

1≦N≦100

Input

The input is given from Standard Input in the following format:

N

Output

Print the necessary number of candies in total.

Sample Input 1

3

Sample Output 1

6

The answer is 1+2+3=6.

Sample Input 2

10

Sample Output 2

55

The sum of the integers from 1 to 10 is 55.

Sample Input 3

1

Sample Output 3

1

Only one child. The answer is 1 in this case.

Solution in Java7 (OpenJDK 1.7.0) (judge verdict: Accepted)

import java.util.*;
public class Main {
	
	private static List<String> hateList = new ArrayList<String>();
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String in = sc.nextLine();
		int seito = Integer.parseInt(in);
		int count = 0;
		for (int i = 1;i <= seito; i++){
			count = count + i;
		}
		System.out.println(count);

	}
 
}