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 Java (OpenJDK 1.8.0) (judge verdict: Wrong Answer)


import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int n;
        int sum = 0;
        n = input.nextInt();
        if (n == 1) {
            System.out.print("1\nOnly one child. The answer is 1 in this case.\n");
        } else if (1 < n && n <= 6) {
            for (int i = 1; i <= n; i++) {
                sum = sum + i;
            }

            System.out.print(sum + "\nThe answer is ");
            for (int i = 1; i <= n; i++) {
                System.out.print(i + " + ");
            }
            System.out.println(" = " + sum);
        } else {
            if (6 < n) {
                for (int i = 1; i <= n; i++) {
                    sum = sum + i;
                }
                System.out.printf("%d\nThe sum of the integers from 1 to %d is %d. \n", sum, n, sum);
            }
        }

    }
}