list($max_yasai, $max_niku, $c, $total) = explode(" ", trim(fgets(STDIN)));

$sub_total = 0;

for($yasai=0; $yasai<=$max_yasai; $yasai++){
    
    $niku = $yasai*$c;
    $sub_total = $yasai + $niku;
    if ($sub_total > $total) echo $yasai-1."\n";
    
}