A+B Format

Calculate a+b and output the sum in standard format -- that is, the digits must be separated into groups of three by commas (unless there are less than four digits).

Input Specification:

Each input file contains one test case. Each case contains a pair of integers a and b where −. The numbers are separated by a space.

Output Specification:

For each test case, you should output the sum of a and b in one line. The sum must be written in the standard format.

Sample Input:

-1000000 9

Sample Output:

-999,991

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int a = input.nextInt();
        int b = input.nextInt();
        input.close();
        int sum = a + b;
        if (sum < 0) {
            System.out.print("-");
            sum = 0 - sum;
        }
        String str = String.valueOf(sum);
        int length = str.length();
        StringBuffer stringBuffer;
        if (length <= 3) {
            System.out.print(str);
        } else if (length <= 6) {
            stringBuffer = new StringBuffer(str);
            stringBuffer.insert(length - 3, ",");
            System.out.println(stringBuffer.toString());
        } else {
            stringBuffer = new StringBuffer(str);
            stringBuffer.insert(length - 3, ",");
            stringBuffer.insert(length - 6, ",");
            System.out.println(stringBuffer.toString());
        }
    }
}