<?php
$input = file('input', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
$input = array_map('str_split', $input);

$chunkPairs = [
    ')' => '(',
    ']' => '[',
    '>' => '<',
    '}' => '{',
];
$illegalValues = [
    ')' => 3,
    ']' => 57,
    '}' => 1197,
    '>' => 25137,
];
$illegalValue = 0;
foreach ($input as $line) {
    $tmpBuffer = [];
    foreach ($line as $charPos => $char) {
        if (in_array($char, array_values($chunkPairs))) {
            $tmpBuffer[] = $char;
        }
        if (in_array($char, array_keys($chunkPairs))) {
            $lastBufferItem = array_pop($tmpBuffer);
            if ($chunkPairs[$char] !== $lastBufferItem) {
                $illegalValue += $illegalValues[$char];
                continue 2;
            }
        }
    }
}
echo $illegalValue; //366027