<?php
$input = '22.5+5.1=';
$num = 0;
$x = 0.1;
$x *= 0.1;
PD9waHAKCmVycm9yX3JlcG9ydGluZygtMSk7Cm1iX2ludGVybmFsX2VuY29kaW5nKCd1dGYtOCcpOwoKJGlucHV0ID0gJzIyLjUrNS4xPSc7CiRpbnB1dExlbmd0aCA9IG1iX3N0cmxlbigkaW5wdXQpOwokbnVtID0gMDsKCiR4ID0gMC4xOwokeCAqPSAwLjE7CnZhcl9kdW1wKCR4KTs=