0) {
$n = (int)$_POST['num'];
$sum = 2; $count = 1; $i = 3;
echo "Prime numbers:
2";
while ($count < $n) {
$isPrime = true;
for ($j = 2; $j <= sqrt($i); $j++) {
if ($i % $j == 0) { $isPrime = false; break; }
}
if ($isPrime) {
echo " $i";
$sum += $i;
$count++;
}
$i++;
}
echo "
Sum of first $n primes: $sum";
} elseif (isset($_POST['submit'])) {
echo "Please enter a valid positive number.";
}
?>