const input = require('fs').readFileSync('/dev/stdin', 'utf-8').trim();
let nums = input.split(/\r?\n/).map(str => str.split(" ")).map(pair => pair.sort(function(a, b){ return a-b; }));
for (let i = 0; i < nums.length-1; i++) {
  console.log(nums[i].join(" "));
}

