<?php

error_reporting(-1);

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

for ($month = 1; $month <= 20; $month ++) {
	    
	    $creditBalance = ( $creditBalance * $percent ) + $servicePayment - $monthlyPayment;
	    $paymantTotal =  $paymantTotal + $monthlyPayment;
	    echo "($month) месяц спустя: долг = ($creditBalance) руб, выплачено всего ($paymantTotal) руб \n";
	    
	    if ($creditBalance < 0) {
	    	echo "С меня хватит!\n";
	    	break;
	    }
}