dwarfs

<?php
$input = readline();
$dwarfs = [];
while ($input !=="Once upon a time"){
    $args = explode(" <:> ", $input);
    $name = $args[0];
    $hatColor = $args[1];
    $physics = intval($args[2]);

    if (!key_exists($hatColor,$dwarfs)){
        $dwarfs[$hatColor][$name] = $physics;
    }
    elseif (key_exists($hatColor,$dwarfs) && key_exists($name,$dwarfs[$hatColor])){
        if ($dwarfs[$hatColor][$name]<$physics){
            $dwarfs[$hatColor][$name] = $physics;
        }
    }
    else {
        $dwarfs[$hatColor][$name] = $physics;
    }

    $input = readline();
}



foreach ($dwarfs as $hat=>$dwarfName){
    foreach ($dwarfName as $dName=>$power){
        echo "($hat) $dName <-> $power" .PHP_EOL;
    }
}