<?php

error_reporting(-1);

$creditBalance = 65700;
$percent = 1.05;
$servicePayment = 1200;
$monthlyPayment = 3500;
$paymentTotal = 0;

for ($month = 1; $month <= 25; $month ++) {
	$creditBalance = ( $creditBalance * $percent ) + $servicePayment;
	$creditBalance = $creditBalance - $monthlyPayment;
	$paymentTotal = $paymentTotal + $monthlyPayment;
	
	if ($creditBalance < 0) {
		$paymentTotal = $paymentTotal + $creditBalance;
		$creditBalance = 0;
		echo "Кредит погашен за {$month} месяцев, айфон обошёлся в {$paymentTotal} рублей.\n";
		break;
	}
	
	echo "{$month} месяц спустя: долг = {$creditBalance} руб, выплачено всего {$paymentTotal} руб. \n";
}