<?php

declare(strict_types=1);

\$input = <<<\'PHP\'
xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))
PHP;

final readonly class Computer
\{
    public function process(string \$input): int
    \{
        return array_reduce(
            \$this->getInstructions(\$input),
            static fn (\$result, \$instruction) => \$result + \$instruction->calculate(),
            0,
        );
    \}

    /**
     * @return array<array-key, Instruction>
     */
    private function getInstructions(string \$input): array
    \{
        \$matches = [];

        preg_match_all(\'/mul\\(\\d+,\\d+\\)/\', \$input, \$matches);

        return array_map(
            static fn (string \$instruction) => new Instruction(\$instruction),
            \$matches[0],
        );
    \}
\}

final readonly class Instruction
\{
    public function __construct(
        private string \$value,
    ) \{\}

    public function calculate(): int
    \{
        \$matches = [];
        preg_match_all(\'/\\d+/\', \$this->value, \$matches);

        [\$left, \$right] = \$matches[0];

        return (int) \$left * (int) \$right;
    \}
\}

\$computer = new Computer();

\$computer->process(\$input);