<?php

error_reporting(-1);

function calculatePayments($credit, $percent, $service, $monthly, $paymentTotal) {

	for ($month = 1; $month <= 20; $month ++) {
 
	$compulsoryPayment = ( $credit * $percent ) + $service;
 
		if ($compulsoryPayment > $monthly) {
			$credit = $compulsoryPayment - $monthly;
			$paymentTotal = $paymentTotal + $monthly;
		}
 
		elseif ($compulsoryPayment < $monthly) {
		   	$credit = $credit - $credit;
		   	$paymentTotal = $paymentTotal + $compulsoryPayment;
		   	break;
		}
	}
    return $paymentTotal;
}

$alfaBankTotal = calculatePayments(39999, 1.04, 500, 5000, 0);
$privatBankTotal = calculatePayments(39999, 1.03, 1000, 5000, 0);
$homeCreditTotal = calculatePayments(39999, 1.02, 0, 5000, 0) + 7777;

echo "AlfaBank = $alfaBankTotal\n";
echo "PrivatBank = $privatBankTotal\n";
echo "HomeCreditBank = $homeCreditTotal\n";

?>