Problem:
Swapping Two Numbers

Write a program which reads two integers x and y, and prints them in ascending order.

Input

The input consists of multiple datasets. Each dataset consists of two integers x and y separated by a single space.

The input ends with two 0 (when both x and y are zero). Your program should not process for these terminal symbols.

Output

For each dataset, print x and y in ascending order in a line. Put a single space between x and y.

Constraints

0 ≤ x, y ≤ 10000

the number of datasets ≤ 3000

Sample Input

3 2
2 2
5 3
0 0

Sample Output

2 3
2 2
3 5

Solution in JavaScript (judge verdict: Accepted)

"use strict";
process.stdin.resume();
process.stdin.setEncoding('utf8');

var lines = []
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});

reader.on('line', (line) => {
    lines.push(line)
});

reader.on('close', () => {
    lines.forEach(function (line) {
	if (line==="0 0") {
	    return;
	}
	var l = line.trim().split(' ').map(x=>parseInt(x));
	console.log(l.sort((a,b)=>a-b).map(x=>x.toString()).join(' '));
    })
});