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)

var lines = [];
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', function (line) {
  var a = line.split(' ');
  var c = parseInt(a[0],10);
  var d = parseInt(a[1],10);
  if(c==d && c==0)
    process.exit();
  if(c>d)
    console.log(d+" "+c);
  else
    console.log(c+" "+d);
});
process.stdin.on('end', function () {
});