<?php

error_reporting(-1);

$creditBalance = 40000;
$percent = 1.03;
$servicePayment = 1000;
$monthlyPayment = 5000;
$paymentTotal = 0;

for ($month = 1; $month <= 20; $month ++) {
	
$compulsoryPayment = ( $creditBalance * $percent ) + $servicePayment;
	
	if ($compulsoryPayment > $monthlyPayment) {
		$creditBalance = $compulsoryPayment - $monthlyPayment;
		$paymentTotal = $paymentTotal + $monthlyPayment;
	}
	
    elseif ($compulsoryPayment < $monthlyPayment) {
    	$creditBalance = $creditBalance - $creditBalance;
    	$paymentTotal = $paymentTotal + $compulsoryPayment;
    	echo "Оплатил айфон, можно и на комплебахтер кредит брать\n";
    }
    
    elseif ($creditBalance >= 0) {
    	break;
    }

   echo "{$month} месяц спустя: долг = {$creditBalance} руб, выплачено всего {$paymentTotal} руб. \n";
   
}

?>