<?php
 
$t = (int)fgets(STDIN);
 
for($i = 0; $i < $t; $i++) {
 
    $parts = explode(' ', trim(fgets(STDIN)));
 
    $x1 = $parts[0];
    $y1 = $parts[1];
    $r1 = $parts[2];
 
    $parts = explode(' ', trim(fgets(STDIN)));
 
    $x2 = $parts[0];
    $y2 = $parts[1];
    $r2 = $parts[2];
 
    $distance = sqrt(pow($x1 - $x2, 2) + pow($y1 - $y2, 2));
 
    $result = $r1 + $r2 - $distance;
 
    if($result > 0) {
        echo number_format($result, 2, '.', '') . "\n";
    } else {
        echo "0.00\n";
    }
 
}

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MwozIDMgMwozIC0xIDQKLTMgLTMgMwotMSAyIDUKMyAzIDIKLTMgLTMgMQ==

3
3 3 3
3 -1 4
-3 -3 3
-1 2 5
3 3 2
-3 -3 1