<?php

$guests = intval(readline());
$prisePerGuest = floatval(readline());
$partyBudget = floatval(readline());

if ($guests >= 10 && $guests <= 15) {
    $prisePerGuest *= 0.85;
} else if ($guests > 15 && $guests <= 20) {
    $prisePerGuest *= 0.80;
} else if ($guests > 20) {
    $prisePerGuest *= 0.75;
}
$cakePrice = $partyBudget * 0.10;
$totalPrice = $guests * $prisePerGuest + $cakePrice;

if ($partyBudget >= $totalPrice) {
    $diff =  ($partyBudget - $totalPrice);
printf("It is party time! %.2f leva left.",$diff);
} else {
    $diff2 = ($totalPrice - $partyBudget);
  printf("No party! %.2f leva needed.",$diff2);
}