<?php

error_reporting(-1);

function chooseBank($percent, $comission, $openPayment) {
	
	$creditSum = 39999;
    $payout = 5000;
	$totalPayment = 0 + $openPayment;
	for ($i = 1; $creditSum > 0; $i++) {
		$monthlyPayment =  $creditSum * $percent + $comission;
	    $creditSum = $creditSum + $monthlyPayment;
	    if ($creditSum < 5000) {
	    	$payout = $creditSum;
	    	$creditSum = $creditSum - $payout;
	    	$totalPayment = $totalPayment + $payout;
	    	break;
	    }
	    $creditSum = $creditSum - $payout;
	    $totalPayment = $totalPayment + $payout;
	}
	return $totalPayment;
}

$homoCreditTotal = chooseBank(0.04, 500, 0);
$softbankTotal = chooseBank(0.03, 1000, 0);
$strawberryBankTotal = chooseBank(0.02, 0, 7777);

echo "homoCredit: {$homoCreditTotal} руб.\n";
echo "softbank: {$softbankTotal} руб.\n";
echo "strawberryBank: {$strawberryBankTotal} руб.\n";