<?php
 
error_reporting(-1);
mb_internal_encoding('utf-8');

$input = '567*7+546-111=';
$input2 = '243+257-300+55=';
$inputLength = mb_strlen($input);

$number = 0;
$result = 0;
$op = '';

for($i = 0; $i < $inputLength; $i++) {
	
	$char = mb_substr($input, $i, 1);
	//echo "Result-[{$result}], Number-[{$number}], OP-[{$op}], char-[{$char}]\n";
	
	if (is_numeric($char)) {
		$number = $number * 10 + $char;
		//echo "Result-[{$result}], Number-[{$number}], OP-[{$op}], char-[{$char}]\n";
	} elseif ($char == '*' || $char == '+' || $char == '-' || $char == '=') {
		if ($op == '') {
			$result = intval($number);
			$number = 0;
			//echo "Result-[{$result}], Number-[{$number}], OP-[{$op}], char-[{$char}]\n";
		}
		elseif ($op != '') {
			if ($op == '*') {
				$result *= $number;
			} elseif ($op == '+') {
				$result += $number;
			} elseif ($op == '-') {
				$result -= $number;
			}
			//echo "Result-[{$result}], Number-[{$number}], OP-[{$op}], char-[{$char}]\n";
		}
		$op = $char;
		$number = 0;
		echo "Result-[{$result}], Number-[{$number}], OP-[{$op}], char-[{$char}]\n";
		if ($op == '=') {
			echo "{$input}{$result}";
			exit;
		}
		
	}
}