<?php
$x = readline();
$y = readline();
if ($x > $y) {
$diff = $x - $y;
print($diff);
} else {
$sum = $x + $y;
print($sum);
}
?>
<?php
$x = readline();
$y = readline();
if ($x > $y) {
$diff = $x - $y;
print($diff);
} else {
$sum = $x + $y;
print($sum);
}
?>