<?php
echo '<pre>';
$lines = 10;
$line = 5;
$bomb = 1;
$secret = hash('sha512', 'abcвапрdsd');
$part = floor(strlen($secret) / $lines);
echo 'Part size: '.$part.PHP_EOL;

$bombs = [];
for($i = 0; $i < $lines; $i++) {
    $start = $i * $part;
    $end = $start + $part;
    $salt = hexdec(substr($secret, $start, $start + $end));
    $f = fNum($start + $end);
    echo 'n: '.$salt.' s:'.$start.' e:'.$end.PHP_EOL;
    echo 'b: '.($salt / $f) * $lines.PHP_EOL.PHP_EOL;
}


function fNum($len) {
    $f = '';
    for($i = 0; $i < $len; $i++) $f .= 'f';
    return hexdec($f);
}